His comments are likely to infuriate officers involved in the huge investigation into the alleged plans to detonate bombs on flights. They came as the police made a further arrest in the Thames Valley area under the Terrorism Act 2000. Concern had already been voiced about Government interference after the Treasury last week published the names of 19 suspects whose assets had been frozen after the arrests.

John Reid, the Home Secretary, was also accused of jeopardising a future trial by claiming that the police were confident that the "main players" were in custody.

Mr Prescott's comments came as the Muslim MPs told him that it could take a generation to tackle extremism.

They urged the Government to do more to win the "hearts and minds" of disaffected young British Muslims.

Khalid Mahmood, the MP for Birmingham Perry Barr, said Mr Prescott had briefed the MPs about the police investigation in the wake of last week's arrests. "The assessment was that there will be some people who would face reasonable charges, they have sufficient information to do that," said Mr Mahmood. "Some may face serious charges but some will not."

Neil Gerrard, the Labour MP for Walthamstow, who also attended yesterday's meeting, confirmed that Mr Prescott had briefed them about the investigation. "I would be surprised if everyone arrested was charged," he said. A huge operation is still under way in connection with the investigation. Anti-terrorism police officers have so far raided 46 residential and business premises in London, the West Midlands and Thames Valley.

Police executed two search warrants in Slough yesterday. Officers have also made an extensive search of King's Wood in High Wycombe, Bucks. Police will need to seek a court extension today to detain the suspects for a further period up to a maximum of 28 days, after which they must be charged or released.

A spokesman for Mr Prescott denied that he had discussed the investigation into the alleged terror plot.

"He did take the MPs through some general police procedures but he would not comment on an ongoing investigation," she said.

Almost a week later, and after a downgrading of the terrorist threat, what do ordinary voters now think of those excitable early briefings by John Reid, the home secretary, and Scotland Yard's dramatically voiced belief that it had foiled "mass murder on an unimaginable scale"? Are people still sceptical?

As it turns out, the prime minister would be heartened by the views of the individuals on his doorstep. Unfortunately, the largely sympathetic crowds outside Downing Street are overwhelmingly made up of non-voter tourists. A Brazilian who has lived in London for five years mentions his innocent countryman, Jean Charles de Menezes, shot dead after botched intelligence following 7/7 last year, but says that, relatively speaking, he trusts the authorities more here than in his home city of Sao Paulo. Similarly, American visitors to the capital say they are impressed with the "very British, very discreet" security and the post-alert calm of the population. But they are bewildered by the sceptical reaction of some Britons to what they see as a war.

"We've been looking at your museums," says John LeClaire, from Boston, holidaying with family and friends. "In the first world war there's this blindly patriotic joining of this war that is in a sense pointless. In the second world war there is uniform support for the government once Chamberlain is got rid of. Now you have, what, about 20% of the people who think terror plots are a conspiracy? That's an extraordinary evolution."

"It didn't cross my mind that this was a conspiracy," says Dogan Arthur, also from Boston. "It would show that terrorism is working if people think it's a conspiracy." He adds: "It's remarkable how international a city London is. It's interesting what a presence the Middle East has in London. I don't remember that 10 years ago. There's nowhere in the US where you would get that sense of being in a sea of Muslims."

Thirty five miles north of Downing Street and the average American tourist really would be startled by Bury Park in Luton, a quintessential 1920s English suburb now predominantly populated by British Muslim families. Halal butchers, grocers selling piles of fresh watermelons and fashion stores offering "wedding sarees, langhas and fabrics" line the main street.

"In my opinion it is a cover-up because of what's going on in Lebanon," says Munir Khan. "When you turn on the TV you see innocent people getting killed. This [plot] distracts from that."

A moderate Muslim who has been a member of the Labour party for nearly 20 years, Khan quit about eight months ago to join the Lib Dems. He does not trust the evidence coming out of Pakistan in relation to this latest alleged terror plot. "The Pakistan government will say anything for money," he says. "If the UK government gives them money to say something, they will say it."

Suspicion and (often internet-fuelled) talk of conspiracies is no longer the prerogative of the young, it seems. According to Khan, it has been noticeable that older Muslims, traditionally engaged in mainstream politics in a way that their children are not, have talked openly of their anger and distrust of the government in recent months.

Scepticism about the plot is shared by many in the area and not just by Muslims, says Qurban Hussain, a local resident and the deputy leader of Luton borough council. "People are definitely sceptical. They are not sure whether these claims are just to clamp down on British Muslims. Is it scaremongering tactics by the government or another reason to harass more innocent people?

"It's a perception held by a lot of my constituents of all backgrounds. When you look back on the WMD, the information was wrong. Then we have the case of Jean Charles de Menezes. We picked up the wrong person altogether. Then the raid in Forest Gate in which a man was shot. There are so many cases people can refer to. It makes them feel they cannot trust the government."

Reassuringly for Labour, the overwhelming majority of people of all faiths I speak to in London, Luton and further up the M1, give a pragmatic, sensible-sounding "wait and see" response to questions about whether they believe that this alleged terror plot is a genuine threat.

"It is in the government's best interests to look after the people of this country. If they hear of a threat, they have every right to close things down," says Usman Hussain, 21, inside a barber's in Bury Park. On the window is a poster advertising a talk on the "crisis in Lebanon". The star guest speaker is billed as a member of Hizb ut-Tahrir, the radical Islamist group. Does Usman believe there was a terrorist plot to blow up planes? "I don't really know. We've been given no evidence yet. It could go either way."

But this general pragmatism is heavily steeped in scepticism everywhere I go, and not just among British Muslims. Jerry Thornton, from Wiltshire, is with the tourists outside Downing Street. "There is so much we don't know. It [the government] is such a secretive organisation. They are all colluding together. Some of it's for our own protection, but I believe a lot of it is spin. I accept during the investigation they can't tell the whole truth but we'd like to know exactly what happened and how it was foiled."

Stopping at the motorway services just north of Luton, John Jeffreys is unsure whether he trusts the government's line. "It's difficult to know. A lot of these terror alerts seem to coincide with an announcement about ID cards for instance. This time there obviously was some sort of plot but we don't know how significant it was. I don't trust the government at all. There's no doubt that Blair lied about the weapons of mass destruction before Iraq."

"It's propaganda, isn't it?" chips in his mate, Mick Perrone, 31. "It gets the whole nation on alert."

What can the government do to restore trust? In a time of endlessly slippery conspiracy theories, how can it show that the terror plot was genuine? "They must come up with the proof," says Khan. Other Muslim voters argue that the first step the government must take to restore levels of trust is to reform its foreign policy. Again and again, Muslim voters point to what they see as the government's "double standards" in dealing with other Islamic countries and disputes in Iraq, Afghanistan, Palestine, Kashmir and now Lebanon.

Muslim voters say they are also angered by the government's - and George Bush's - use of the term "Islamic terrorism". "Why Islamic? Look at Northern Ireland. Who was saying 'Christians' there?" says Khan.

By chance an Irish family on holiday from Belfast pull into the services on the M1 while I'm there. "This [plot] could be make-believe, so the government can say, 'Look what we're doing to fight the terrorists,'" says Joanne Burrows. "There must have been something to arrest 23 people, but plenty of people have done time in Northern Ireland for doing nothing".

A majority also wants tougher domestic legislation that would allow police more time to detain suspects while they investigate complex terrorism plots.

Some 69 per cent said that the police should be able to hold suspects for up to 90 days without charge, rather than be bound by the current 28-day limit.

The poll findings will encourage John Reid, the Home Secretary, who has warned the British public that they will have to forgo many of the freedoms and liberties they have grown used to in order to ensure the maximum level of security.

Yesterday Mr Reid highlighted the benefit of European co-operation in the battle against terrorism.

He told a mini-summit of European Union home ministers in London that Europe faced a "very real and persistent threat from a form of terrorism that is unconstrained in its evil. . . and its ability to cause immense harm, death and destruction".

The meeting was "symbolic" of a Europe standing together against the most serious threat faced by modern governments, Mr Reid said.

He contrasted what he called the common EU values of "human rights, democratic freedoms and justice for all" with an "intolerant, violent totalitarianism that seeks to destroy those values, ironically by subverting a religion whose very name stands for peace".

Several of Europe's leading politicians, including Nicholas Sarkozy, the French interior minister, and Wolfgang Schauble, his German counterpart, attended. They agreed that airport checks across Europe had to be harmonised to ensure consistency and prevent terrorists exploiting security gaps.

The survey, carried out for The Spectator magazine, shows that a majority of people now recognises everyday lives will change fundamentally. Seventy three per cent agreed that "the West is in a global war against Islamic terrorists who threaten our way of life".

When asked whether Britain should change its foreign policy in response to terrorism only 12 per cent said it should be more conciliatory, compared with 53 per cent who thought it should become more "aggressive" and 24 per who wanted no change.

People were divided about the Muslim community in Britain. Fifty per cent said "most British Muslims are moderate" while 28 per cent disagreed with the statement and 22 per cent did not know.

While there was strong support for a hard line on terrorism at home, the survey exposed deep-seated distrust of the foreign policies championed by Mr Bush since September 11, 2001. Only 14 per cent believed Britain should continue to align itself with America.

On a recent five-day visit to the United States Mr Blair did nothing to distance himself from Mr Bush - despite pressure to do so from Labour MPs. In the White House he stood shoulder to shoulder with the President, stressing the struggle the West faced against an "arc of extremism" stretching from Afghanistan to the Lebanon.

Some 60 per cent of people thought the war on terrorism would continue for at least 10 years, with 44 per cent of these thinking it would still be going on in 20 years' time.

Fifty per cent of people believed Mr Blair should have broken his holiday to deal with the crisis caused by the arrest of suspects in last week's alleged plot to blow up transatlantic aircraft. Forty three per cent thought he could do the job as well by telephone and e-mail.

Stressing the need for European co-operation, Mr Reid said: "It's very important that the measures that are taken in one country are reflected in other countries because we want equal security for all our countries. We must not have a position where terrorists feel if it is difficult to get through security checks in London, they might be able to go to Paris or Frankfurt or Berlin".

Police declined to give any further details but they revealed that detectives had now searched 46 homes and businesses in London, Thames Valley and the West Midlands and that 22 searches were on-going. A total of 20 vehicles have also been examined.

A total of 24 people are now in custody although police will need to seek an extension to detain them beyond today.

The chaos at airports caused by increased security is understood to have prompted government officials to consider a system of passenger profiling that would select people behaving suspiciously, who have an unusual travel pattern or have a certain ethnic or religious background.

But Chief Superintendent Ali Dizaei, of the Metropolitan Police, one of Britain's most senior Muslim officers, hit out against the move, saying: "It [profiling] becomes hugely problematic when it's based on ethnicity, religion and country of origin. I don't think there's a stereotypical image of a terrorist.

"What you are suggesting is that we should have a new offence in this country called 'travelling whilst Asian'.

"That's unpalatable to everyone. It is communities that defeat terrorism, and what we don't want to do is actually alienate the very communities who are going to help us catch terrorists.

"Timothy McVeigh, the Oklahoma bomber, would have certainly gone through the security system because he was a white male."

Abdul Ahman, vice-chairman of the Muslim Council of Britain's legal affairs committee, described passenger profiling as a "crowd pleaser".

"You cannot help but think 'Wow, we have got to do it... all the people who have done it so far have been brown or Muslim'. The idea that a minority is expendable when the majority is under threat, that has very deep resonance," he said.

"It is the kind of idea that really does lead to a slippery slope where we become the monster that we are supposed to be fighting against.

"We need to have a calm, measured and well thought-out approach. I don't think that this [profiling] falls into that category."

Mr Ahman criticised the Conservative leader, David Cameron and John Reid, the Home Secretary, in particular.

"Cameron's statement that we should be doing more to target Islamic extremism. John Reid saying this is the greatest threat since Hitler... the way it plays out in the public mind is that we have a problem with Muslims because they follow a religion of hatred and violence," he said.

"I think these are the unequivocal messages given out by a lot of the tabloid newspapers. The whole debate becomes very simplistic with these meaningless words like 'Islamic fascism'.

"This is our religion. We thought crimes are supposed to be crimes. You cannot talk about a whole religion or a whole race of people [in this way]. I thought we had left that kind of approach behind 20 years ago.

"There was a 500 per cent increase in hate crimes in the UK after 7/7. I fear for the long-term future. As a Muslim who loves his own country, Britain, I feel very despondent about where this is leading us."

Osama Saeed, Scottish spokesman for the Muslim Association of Britain, said he believed passenger profiling was already happening. "I don't think this is a new policy. I think it's pretty clear there has been profiling going on for some time. It's annoying, it's embarrassing, but it's not new," he said.

Paddy Tomkins, Chief Constable of Lothian and Borders, said there had already been two racist incidents in his force's area - one where a member of a mosque in Livingston was abused and another where graffiti was daubed on an Edinburgh mosque.

"We will not tolerate racism and will pursue racists as a priority, using all the resources we have, and prosecute them through the courts using the full force of the laws available to us," he said.

A Department of Transport spokesman would not confirm or deny that passenger profiling was to be introduced. "In due course we expect to issue new security requirements but we are working out what they are going to say," he said.

The EU's plan on terrorism envisages a directive being drawn up this autumn to implement the scheme, which would enable both regular cleared passengers to get through security checks quicker and enable the security services to check passenger names against warning lists of terror suspects.

The scheme is part of a package of measures agreed yesterday at the meeting called as an act of solidarity in response to last week's arrests in connection to the alleged airline plot.

The ministers were briefed by the director general of MI5, Dame Eliza Manningham-Buller, and the head of special operations at Scotland Yard, assistant commissioner Andy Hayman.

The measures also include:

- An urgent £237,000 research project into how to detect liquid explosives, which were at the centre of last week's alleged plot;

- New moves against internet sites that incite terrorism and detail bomb-making techniques;

- The adoption across Europe of the new British regime of hand luggage checks at airports;

- Further measures to curb radicalisation and recruitment among Europe's Muslim communities;

- A Euro-summit of security services later this month to "pre-empt the terrorists' next plot".

Mr Reid said after the meeting: "What's clear to all of us is that we face a persistent and very real threat across Europe. It is a threat we face here in Britain as individuals and as communities, but it's not unique to the UK. It affects us all across the European Union."

Mr Reid said in considering the use of advanced passenger data it was important to distinguish between "positive profiling" and "ethnic or racial profiling". It was not clear last night how far Britain was prepared to go in signing up to the use of such advanced passenger data but the Home Office has two pilot schemes running, Project Iris and Project Semaphore. The latter involves screening 10 million passengers a year on selected international routes.

The recent Home Office plan to turn the immigration service around also includes proposals for a "trusted traveller" scheme which would allow 40,000 passengers to fast-track through airport security checks by the end of this year with rapid expansion to follow. More stringent security checks however are to be carried out on travellers from "high-risk" countries or routes creating a two-tier system of passengers.

A Spectator/YouGov poll published this morning suggests that a majority - 55% - would be happy to see passenger profiling at airports.

But ministers acknowledged yesterday that some EU countries, particularly France and the Netherlands, want to go much further and introduce explicit checks on Muslim travellers. Claude Moraes, an Asian Labour MEP, said yesterday the random checks he faced travelling around Europe had increased in recent years and warned that assuming that race or religion was a predictor of terrorism was a "recipe for disaster".

Professor Takis Takimidis of Matrix Chambers said yesterday that positive profiling could be a disguised way of racial profiling.

"For instance if the authorities only profile those who have Asian names. But if they profile everybody who is a passenger, I can't see what could be wrong with this. But it's very hard to say whether 'positive profiling' would be problematic without knowing exactly what it is.

"Even if the comparison contains an ethnic element then that might be justified on grounds of national security. On the other hand, if anyone who has a criminal record is stopped that may well be a violation of a person's free movement within the EU. That has nothing to do with discrimination but it may be disproportionate interference. Basically it depends on the circumstances."

The meeting was held as a mid-air "passenger disturbance" on a Washington-bound flight from Heathrow forced the pilot to declare a security emergency.

The United Airlines flight was escorted into Boston by two F15 fighter jets, amid claims of a confrontation between a female passenger and flight crew.

Reports that she had been carrying matches, Vaseline, a screwdriver and a note about al Qaida were later denied, but the incident started a major security alert.

Later an FBI spokeswoman in Boston said the woman was in police custody for allegedly "interfering with a flight crew".

Massachusetts Governor Mitt Romney said the 59-year-old, from the state of Vermont, became so claustrophobic and upset that she needed to be restrained.

In London, Mr Reid refused to be drawn on reported comments by Deputy Prime Minister John Prescott that some of the 24 suspects being held in connection with the alleged plot to bomb airliners could face only minor charges.

But he said police appeared to believe that there was material of a "substantial nature" emerging from inquiries.
Among the measures discussed at the meeting were proposals to make the Internet a "hostile environment" for terrorists.
Other proposals included a requirement to provide similar data on airline passengers on flights in Europe, to that required by the United States and Canadian authorities for passengers travelling to their countries.

Ministers considered "positive profiling" of passengers, carried out before flights, based on "biometric identifiers" such as iris scans or fingerprints.

The ministers also freed up 350,000 euros (£237,000) from the EU budget for research into detecting liquid explosives which the alleged plotters were said to be planning to use.
In closed court hearings last night, anti-terror detectives applied for more time to question 23 of the 24 suspects in custody over the alleged plot.

In each case, officers were presenting evidence to a district judge for him to decide whether it was sufficient to warrant their further detention.

Last night specialist officers were searching woodland in High Wycombe, Bucks, for traces of explosives or explosive tests.

There were claims yesterday that Britain was seeking the fast-track extradition of another suspect in the case, who is being held in Pakistan.

Rashid Rauf, a British citizen and brother of one of those held in the UK, is alleged by the Pakistani authorities to have been a key player in the plot.

Rauf's relatives in Pakistan were reported to have insisted he was harmless. The Home Office refused to say whether it had requested his extradition.

"The observation of human behavior is probably the hardest thing to detect," Waverly Cousin, a former police officer and checkpoint screener who is now the supervisor of the behavior detection unit at one of the airports was quoted as saying.

"You just don't know what I am going to see. Even in its infancy, the paper said, the programme has elicited some protests.

At one airport, passengers singled out solely because of their behavior have at times been threatened with detention if they did not cooperate, raising constitutional issues that are already being argued in court.

Some civil liberties experts were quoted as saying that the programme, if not run properly, could turn into another version of racial profiling.

Taking a page from Israeli airport security, the transportation agency has been experimenting with this new squad, whose members do not look for bombs, guns or knives. Instead, the assignment is to find anyone with evil intent.

So far, these specially trained officers are working in only about a dozen airports nationwide, including Dulles International Airport here outside Washington, and they represent just a tiny percentage of the transportation agency's 43,000 screeners.

But after the reported liquid bomb plot in Britain, agency officials say they want to have hundreds of behavior detection officers trained by the end of next year and deployed at most of the nation's biggest airports.

"The observation of human behavior is probably the hardest thing to defeat," said Waverly Cousin, a former police officer and checkpoint screener who is now the supervisor of the behavior detection unit at Dulles. "You just don't know what I am going to see."

Even in its infancy, the program has elicited some protests.

At one airport, passengers singled out solely because of their behavior have at times been threatened with detention if they did not cooperate, raising constitutional issues that are already being argued in court. Some civil liberties experts said that the program, if not run properly, could turn into another version of racial profiling.

Other concerns were raised this week by two of the foremost proponents of the techniques, a former Israeli security official and a behavioral psychologist who developed the system of observing involuntarily muscular reactions to gauge a person's state of mind.

They said in interviews that the agency's approach puts too little emphasis on the follow-up interview and relies on a behavior-scoring system that is not necessarily applicable to airports.

"It may be the best that can be done now, but it is not nearly good enough," said Paul Ekman, a retired psychology professor from the University of California, San Francisco, who specializes in detecting lies and deceit, and has helped the T.S.A. set up its program. "We could do much better, and we should because it could save lives."

Agency officials said they recognize that the program, which they call Screening Passengers by Observation Technique, or SPOT, may not yet be perfect. But they added that they were constantly making adjustments and that they were convinced that it was a valuable addition to their security tool chest.

"There are infinite ways to find things to use as a weapon and infinite ways to hide them," said the director of the T.S.A., Kip Hawley, in an interview this week. "But if you can identify the individual, it is by far the better way to find the threat."

The American version of the airport behavior observation program got its start in Boston, said Thomas G. Robbins, former commander of the Logan International Airport police.

After the Sept. 11 attacks in 2001, he said, state police officers there wondered whether a technique they had long used to try to identify drug couriers at the airport might also work for terrorists. The officers observed travelers' facial expressions, body and eye movements, changes in vocal pitch and other indicators of stress or disorientation. If the officers' suspicions were aroused, they began a casual conversation with the person, asking questions like "What did you see in Boston?" followed perhaps by "Oh, you've been sightseeing. What did you like best?"

The questions themselves are not significant, Mr. Robbins said. It is the way the person answers, particularly whether the person shows any sign of trying to conceal the truth.

The Transportation Security Administration, starting last December, decided to try out the approach at about a dozen airports, including Logan. At each airport, it used six officers who had once been routine screeners, had received an extra four days of classroom training in observation and questioning techniques, and had three days of field practice.

T.S.A. officers do not have law enforcement powers, so if they observe someone suspicious, they can chat with the person but cannot conduct a more formal interrogation. That leaves them with the option of requiring the passenger to go through a more intense checkpoint search, as they did with the man at Dulles on Wednesday. Or if the suspicion is serious enough, they call the local police assigned to the airport to take over the inquiry.

In nine months - a period in which about seven million people have flown out of Dulles - several hundred people have been referred for intense screening, and about 50 have been turned over to the police for follow-up questioning, said John F. Lenihan, the transportation agency's security director at Dulles.

Of those, half a dozen have faced charges or other law enforcement follow-up, he said, because the behavior detection officials succeeded in picking out people who had a reason to be nervous, generally because of immigration matters, outstanding warrants or forged documents.

"It is an extra layer of security that is on top of what we have," Mr. Hawley said of the program.

But Rafi Ron, the former director of security at Ben-Gurion International Airport in Tel Aviv, who was a consultant who helped train the officers at Logan Airport, said that the agency's system, while a welcome improvement to airport security, was still flawed. Most importantly, he said, too few of the passengers pulled aside were more formally questioned as in the Israeli system, and when questioning was done, it was handled by local police officers who might not have had the necessary behavioral analysis skills.

He cited the case of Richard Reid, known as the shoe bomber, who aroused suspicion when he arrived at Charles de Gaulle International Airport outside Paris, but was ultimately allowed to board after the police had questioned him.

"If you don't do the interviews properly, you are missing what is probably the most important and powerful part of the procedure," he said.

Another concern was raised by Mr. Ekman, who developed some of the facial analysis tools that the T.S.A. screeners were being trained to use - for example, fear is manifested by eyebrows raised and drawn together, a raised upper eyelid and lips drawn back toward the ears. He said the point system that the T.S.A. had set up was based on facial reactions that occurred in sit-down interviews, not while people were standing in line at the airport.

"We have no basis other than the seat of our pants to know how many points should be given to any one thing," he said.

The technique has already produced at least one lawsuit, filed in Boston. The state police at Logan Airport there happened to pick out, based on behavior observations, the national coordinator of the American Civil Liberties Union's Campaign Against Racial Profiling.

The coordinator, King Downing, who is black, had just left a flight when he stopped to make a phone call and noticed that a police officer was listening in, the lawsuit says. When the call ended, the officer demanded Mr. Downing's identification, asking again as he approached a taxi and then telling him he would be "going downtown" unless he provided it. Mr. Downing was let go after he showed his identification, but the encounter led to the lawsuit.

"There is a significant prospect this security method is going to be applied in a discriminatory manner," said John Reinstein, an A.C.L.U. lawyer handling Mr. Downing's case. "It introduces into the screening system a number of highly subjective elements left to the discretion of the individual officer."

T.S.A. officials, who were not involved in the incident with Mr. Downing, said they recognized that people at airports were often agitated - they may be late for flights, taking an emergency trip or simply scared of flying.

They said they were committed to ensuring the program was not discriminatory and would be monitoring the work of the SPOT teams to ensure that the officers were acting upon the established indicators and not any racial or ethnic bias.

But they acknowledged that some entirely innocent parties, like the man at Dulles on Wednesday, would probably be pulled aside. That passenger, whom officials would not identify, was allowed to catch his flight after a thorough search.

"It is like throwing a big fishing net over the side of the boat: You catch what you catch," said Carl Maccario, an agency official helping manage the SPOT teams. "But hopefully within that net is a terrorist."

According to an affidavit and passenger accounts, Mrs. Mayo began pacing the plane from the front to aft lavatory and asked a flight attendant, "Is this a training flight for United Flight 93?" -- the flight hijacked on September 11, 2001, that crashed into a Pennsylvania farm field.

Mrs. Mayo demanded to speak with an air marshal, saying the contents of her bag would be of interest. Her bag contained a screwdriver, body lotion, several cigarette lighters and a bottle of water. The affidavit did not say how she smuggled the items on board, despite being screened twice at London's Heathrow Airport.

When confronted by the captain, Mrs. Mayo made a reference to bomb assembly, saying, "There are six steps to building some unspecified thing."

"She made reference to being with people associated with two words," the affidavit said. "She stated that she could not say what the two words were because the last time that she had said the two words she had been kicked off a flight in the United Arab Emirates."

The captain ordered her restrained, and the passengers and a flight attendant tackled her and placed her hands in plastic cuffs.

Officials in the United Kingdom and the U.S. are on heightened alert after dozens of British citizens were arrested last week, accused of plotting to smuggle liquid explosives aboard trans-Atlantic flights.

Mrs. Mayo told passengers she was an undercover reporter testing security to see whether she could sneak restricted items on board.

As a columnist for the Daily Times of Pakistan, Mrs. Mayo criticized President Bush -- calling him "a president not elected by the people" -- and the war in Iraq. "The folksongs of the 1960s will never be written again because of President George Bush. He has hampered the liberties of my country in the name of September 11. Songs now can only talk of patriotism they cannot mention peace," she wrote.

Passengers initially assumed the men who restrained Mrs. Mayo were federal air marshals but yesterday said they were passengers recruited by flight attendants who provided them with handcuffs.

"They were asked to be on the alert in case we need you," said Joan Bartko, a passenger who was traveling with her family.

Mrs. Mayo "took down her slacks and started taking down her underwear, and that's when they got her. They were just passengers on the plane who immediately helped," Mrs. Bartko said.

"It looks like there were four items containing liquids," said TSA spokeswoman Amy von Walter. A machine that security checkpoint screeners use to test for explosives registered positive results for two containers, and a canine team also got a positive hit, she said.

The TSA screening looks for a range of explosives residue, some of which can be found on common household items, said TSA spokesman Darrin Kayser.

Airport manager Larry Salyers said he was told the woman was a 28-year-old of Pakistani descent who had moved to West Virginia from Jackson, Mich.

No charges were filed against the woman, who was taken from the airport by federal authorities at 5 p.m., Salyers said.

The woman was cooperative, officials said.

The woman's mother told the Associated Press that her daughter, who is four months pregnant and lives in Barboursville, W.Va., was targeted because of her nationality and Islamic headcover.

"It was not only a false alarm, it was racial discrimination because there was nothing," Mian Qayyum said, refusing to name her daughter.

"She just had water to drink because she is pregnant and she had a face wash that had a drop of bleach on it," Qayyum said from her home in Jackson.

The FBI did not immediately return messages Thursday night seeking comment on the racial profiling allegations.

A screener noticed a bottle in a woman's carry-on bag as she was going through security before her 9:15 a.m. flight to Charlotte, N.C., said Tri-State Airport Authority President Jim Booton.

One bottle contained a gel-type facial cleanser, FBI spokesman Jeff Killeen said.

"Anytime a prohibited item is brought to a checkpoint, then you are going to be immediately more interested in that bag," Kayser said.

The woman had purchased a one-way ticket to Detroit by way of Charlotte on Wednesday, Salyers said.

The flight was allowed to leave for Charlotte, and the terminal was evacuated at 11:25 a.m., officials said.

Commercial airline service was suspended, and about 100 passengers and airport employees were ordered to leave the terminal, Booton said.

Two airlines - Comair and US Airways Express - serve the airport.

After the evacuation, many passengers decided to stay and wait it out.

"We bought them pizza, soft drinks ... tried to make them comfortable as could be in this situation," Salyers said. "We had them in the parking lot, under trees, in conference rooms, the firehouse."

U.S. authorities banned the carrying of liquids onto flights last week after British officials made arrests in an alleged plot to blow up U.S.-bound planes using explosives disguised as drinks and other common products.

Joy and John Cloutre of Ulysses, Ky., were waiting to begin the first leg of their trip to the southeast Asian country of Brunei when the evacuation order came.

Joy Cloutre told the Herald Dispatch of Huntington that her family didn't want her to leave because of terrorism in the region. "And then we don't even get out of Huntington without something like this happening."