Most flee to areas of their own sect or ethnic group, but Omar - who was afraid to give his real name - came to Kurdistan because it is Iraq's safest region, even though he has no friends or relatives here. "I speak no Kurdish but some people here who served in the Iraqi army speak Arabic. Everyone's very hospitable."

"About a thousand Sunni families lived in Husseiniya, but almost all have left by now," he says. A car mechanic, he has not yet found work in Kurdistan. He pays $150 (£80) a month out of the family's savings for their room and toilet.

In another part of the bleak village of Sewys, on the windy plain east of Kurdistan's capital Irbil, a Kurdish estate agent explains why he left Mosul, Iraq's third largest city. An armed Arab came into the office where he worked as an estate agent in a mixed Arab-Kurdish area. "He told me they were part of the resistance to the Americans and needed my house for an operation. When I refused, the gunman rang his friend who was in a car outside and said 'Let's go to his house anyway'." Samir (who declines to give his last name) closed his office and drove straight to Irbil.

On the phone his wife told him three cars had appeared at the house and the men inside were watching it. Fortunately, they did not enter and his wife left for Irbil two days later with their children.

Samir produces an A4 piece of paper he says was sent to a relative last month. It begins with a few verses of the Qur'an and the phrase in Arabic: "The people mentioned below must be killed because they are drug dealers, spies, or traitors working against Iraq." Twelve names and addresses follow. Two are identified as "peshmerga" (the Kurdish militia), one as a "member of the national guard", and the fourth as an "unpatriotic Kurd".

There is no way of telling whether the death list, which is signed starkly "Intelligence Committee", is authentic but Samir's family took no chances. "My brother's name is on the list. He left immediately for Syria," says Samir's wife.

Sewys's previous population of 3,000 has increased by half in the last few months. Escapees choose it because house rents are lower than in Irbil.

A similar increase is affecting Ein Kawa, Irbil's mainly Christian enclave, which has seen an influx of 7,000 families from Baghdad and Mosul in the last few months. Schools have had to hire Arabic-speaking teachers and add an afternoon shift in Arabic. The church gives $150 a month to Christians who need it.

A foreign-funded NGO, the Public Aid Organisation, sends social workers out to give legal advice and assess what help the displaced need. Iraq still has a system of subsidised food rations, dating from the Saddam Hussein era, but families who leave their home areas have difficulty re-registering for it elsewhere.

Karim Sinjari, Kurdistan's interior minister, says the region has received close to 50,000 people since the crisis began. "The Christians have relatives here. Kurds are similar. It's the Arabs who have difficulties," he says.

Dreading an even bigger influx if central and southern Iraq collapse into all-out civil war, he has approached the UN's refugee agency for help. "We won't close our borders but if the numbers soar, what can we do? The UN says we shouldn't resort to refugee camps, but we say where can we put them?"

The Kurdish government offers no financial help to the displaced. But it gives jobs to the doctors, professors, and engineers among them. "We encourage them to stay here rather than go to Syria or Jordan," Mr Sinjari says.

The International Organisation of Migration reported this month on a survey of the displaced in six of Iraq's 18 governorates. In Kirkuk, 55% had no access to healthcare and 70% of children had not been vaccinated.

IOM started emergency aid to the displaced this summer with US funding. But with no sign of the number of displaced falling, it is asking for a further $20m to continue providing assistance.

Annan said the departure of US troops from Iraq "should not lead to a further deterioration of the situation."

The goal should be to leave when Iraqi authorities can ensure a "reasonable, secure environment," he said.

Annan, whose term ends as the head of the global body on January 1, said the war in Iraq and the failure of the UN Security Council to prevent the invasion by US-led forces was the biggest regret he had in his 10-year tenure.

"I firmly believe that the war could have been avoided," he told reporters at the United Nations in Geneva.

"The inspectors should have had a bit more time."

The third option, which calls for a swift withdrawal of U.S. troops, is unlikely to be approved by the Bush administration as it is likely to push Iraq directly into a full-blown and bloody civil war.

However, a combination of the first two options could also backfire if Iraqis suspect it is really a way for the United States to keep a long-term presence in Iraq.

The review comes at a time when escalating violence is causing Iraq policy to be reconsidered by both the White House and the congressionally chartered, bipartisan Iraq Study Group.

The Pentagon study will feed into the White House review, but military officials have made it clear that they are operating independently.

Appeal controversy

Chief defence lawyer Khalil al-Dulaimi told the BBC his team had been prevented from filing appeal papers. Under Iraqi law it must be done within a month of sentencing.

However, the chief prosecutor, Jafaar al-Mousawi, has told the BBC it was a fair trial.

He said the appeal would be automatic because a death sentence had been passed - and that the relevant papers had been sent to the appeal court.

Mr al-Mousawi's claims that the trial was fair were echoed by Iraqi Foreign Minister Hoshyar Zebari.

"We believe strongly that the trial was fair and Saddam Hussein had every right to defend himself," he told the BBC.

"The procedure, I think, in the court, was witnessed by the whole world."

"It wasn't something done behind closed doors or through summary justice, as was the case during his rule. And we stand really by the court's verdict, and we believe the trial was just and fair."

Historical record

Saddam Hussein and seven co-defendants all faced charges of crimes against humanity relating to the deaths of 148 people in the mainly Shia town of Dujail following an assassination attempt on the Iraqi leader in 1982.

Two of his co-defendants also received death sentences.

Saddam Hussein is now being tried on a different set of charges relating to a military campaign against ethnic Kurds in the late 1980s, in which more than 180,000 people are alleged to have died.

The New York-based HRW group said the trials were among the most important since the Nazi trials in Nuremberg after World War II.

They "represent the first opportunity to create a historical record concerning some of the worst cases of human rights violations, and to begin the process of a methodical accounting of the policies and decisions that give rise to these events", the report said.

The BBC's David Loyn in Baghdad says HRW's disappointment is the greater because it considers the Iraqi court to have failed to take account of the international significance of this trial and the one currently under way.

Supporters of war crimes trials say that they can improve healing after conflict, our correspondent says, but like so much else in post-Saddam Iraq, his trial does not seem to have achieved that lofty ambition.

Lawyers murdered

HRW based its scathing assessment on extensive observation of court proceedings, and interviews with judges, prosecutors, defence lawyers and court administrators involved.

The trial took just over one year to complete and was the first case brought before the Iraqi High Tribunal.

Proceedings were marked by frequent outbursts by both judges and defendants.

Three defence lawyers were murdered, three judges left the five-member panel and the original chief judge was replaced.

Defence lawyers boycotted proceedings but HRW said court-appointed counsel that took their place lacked adequate training in international law.

In addition, important documents were not given to defence lawyers in advance, no written transcript was kept and paperwork was lost, said HRW.

The defence was also prevented from cross-examining witnesses and the judges made asides that pre-judged Saddam Hussein.

'Indefensible penalty'

The US-led Coalition Provisional Authority decided that the Dujail trial would be held by an Iraqi court in Iraq, ruling out an international tribunal or a mixed Iraqi-international court under UN auspices, the HRW report said.

Because Iraqi lawyers and judges had been isolated from international criminal law, this decision resulted in a court that lacked the expertise to prosecute crimes against humanity on its own, the report said.

Defence counsel come under criticism in the report for trying to use the court as a political platform.

Meanwhile, the Iraqi government was guilty of influencing the independence of the judges, the report said, to the extent that the first chief judge resigned.

"Under such circumstances the soundness of the verdict is questionable," HRW concludes.

"In addition, the imposition of the death penalty - an inherently cruel and inhumane punishment - in the wake of an unfair trial is indefensible."

Mr Moualem pledged cooperation in tackling the growing violence sweeping the country, saying Syria was prepared to work "hand in hand to achieve the security of brother Iraq".

He also signed an accord with his Iraqi counterpart, Hoshiyar Zebari, agreeing that US troops should remain in Iraq for the time being. Previously, he had called for a timetable for the withdrawal of 140,000 US troops.

The accord contained wording used by the Iraqi and US governments, saying troops should gradually withdraw once they were not needed.

Iraq and the US have accused Syria of not doing enough to stop foreign Islamist fighters and weapons crossing the long and porous Iraqi-Syrian border.

Syria says sealing the border is impossible, insisting Iraq must do more to patrol its side.

The Iraqi president, Jalal Talabani, will this weekend fly to Tehran for a three-way summit including Syria. The talks - an initiative of the Iranian president, Mahmoud Ahmadinejad, will focus on how Iraq's neighbours can help staunch the sectarian bloodshed in the country.

The summit initiative, a sign of Iran's diplomatic clout in the region, comes at a time when the US is debating whether to bring in Iran and Syria into diplomatic efforts to calm the situation in Iraq.

Iran and Syria, however, are not waiting for Washington, and have taken the initiative.

The former US secretary of state James Baker, who is leading the Iraq Study Group, has made clear his desire to bring Iran - once described by George Bush as part of the "axis of evil" - into the diplomatic process. Tony Blair has also called for "a new partnership" with Iran and Syria.

However, Mr Bush has insisted that Iran suspends nuclear enrichment before the start of any dialogue, while Syria has also been frozen out because of its links with alleged terrorist organisations such as Hizbullah in Lebanon.

Press reports said Mr Ahmadinejad first proposed three-way negotiations last year, but was refused by the then Iraqi prime minister, Ibrahim Jafari. Mr Jafari and his advisors feared the US would oppose giving Iran any role in Iraq, and doubted Syria's intentions.

The US has sought to play down the significance of the three-way summit, and the state department spokesman, Tom Casey, yesterday said previous statements by Iranian and Syrian leaders had not proved productive.

"What we'd like to see the Iranian government do is desist, first and foremost, from negative actions it's taken in Iraq," Mr Casey added. "As we have always said with respect to the Syrians ... the problem is not what they say, the problem is what they do."

Syria and Iraq are restoring full diplomatic ties following an agreement struck in principle some months ago.

Saddam Hussein and the late Syrian president Hafez al-Assad, leaders of rival wings of the Arab nationalist Ba'ath party, severed ties when Syria sided with Iran during the 1980-1988 Iran-Iraq war.

As diplomatic efforts on Iraq gathered momentum, the UN secretary-general, Kofi Annan - who angered Washington by describing the war in Iraq as illegal - said the US was "trapped".

He urged Washington to carefully consider when would be the best time to pull out of Iraq so withdrawal did not lead to a further deterioration of security.

"The United States, in a way, is trapped in Iraq," Mr Annan said. "It cannot stay and it cannot leave.

"There are those who maintain that its presence is a problem and there are those who say that if it leaves precipitously, the situation will get worse."