Capt. John Bryson said police think the shootings were either drug-related or some type of retaliation attack. A semiautomatic weapon was used and "multiple, multiple rounds" were fired, he said.

"I think the motivation we're looking at is pretty obvious," he said. "Somebody wanted them dead."

Bryson said he could not remember the last time this many people were killed in once incident - before or after Katrina. "I can't remember five," he said.

Four of the victims - a 16-year-old, a 17-year-old and two 19-year-olds - died at the scene. Another 19-year-old, believed to be the brother of the youngest victim, died later at a hospital, police said.

There was no immediate word if any of the victims had been armed. Their identities were not immediately released.

Terrance Rayly, 23, who was staying in a home nearby, said he heard the shots after getting in from a music club.

"It was like 15 gun shots," he said. "I heard pop, pop, pop, pop, pop."

The shooting left many people feeling unsafe in the poor Central City neighborhood where people sat on porches and discussed the incident Saturday.

"Lord, this is like the sixth person killed around here in the last month," said Monique Jackson, a 27-year-old housekeeper who lives around the corner from the crime scene. "It's getting bad now."

She added: "I don't want to ever hear about a murder ever again. It's just young people doing it to each other."

Crime, including murder, has been creeping back after Katrina emptied the city of its residents when it hit on Aug. 29, flooding 80 percent of New Orleans. Current population estimates vary but the city is believed to have less than half its pre-storm population of about 455,000.

So far, 52 people have been murdered in the city since Jan. 1, half the number of murders at this time last year, Bryson said.

There were only 17 killings in January through March. But the rate picked up after that - there were 13 in April alone, followed by 22 in May and June, including Saturday's killings.

Bryson said the recent spike in murders, which he said was connected to drugs, was not just a "police problem" or a "New Orleans problem."

"It's a Louisiana problem, it's a United States problem," he said. "We're begging the citizens to join with us to coordinate with watch groups."

U.S. intelligence got its first inkling of the plot from the contents of a laptop computer belonging to a Bahraini jihadist captured in Saudi Arabia early in 2003. It contained plans for a gas-dispersal system dubbed "the mubtakkar" (Arabic for inventive). Fearing that al-Qaeda's engineers had achieved the holy grail of terror R&D - a device to effectively distribute hydrogen-cyanide gas, which is deadly when inhaled - the CIA immediately set about building a prototype based on the captured design, which comprised two separate chambers for sodium cyanide and a stable source of hydrogen, such as hydrochloric acid. A seal between the two could be broken by a remote trigger, producing the gas for dispersal. The prototype confirmed their worst fears: "In the world of terrorist weaponry," writes Suskind, "this was the equivalent of splitting the atom. Obtain a few widely available chemicals, and you could construct it with a trip to Home Depot - and then kill everyone in the store."

The device was shown to President Bush and Vice President Cheney the following morning, prompting the President to order that alerts be sent through all levels of the U.S. government. Easily constructed and concealed, mass casualties were inevitable if it could be triggered in any enclosed public space.

Having discovered the device, exposing the plot in which it might be used became a matter of extreme urgency. Although the Saudis were cooperating more than ever before in efforts to track down al-Qaeda operatives in the kingdom, the interrogations of suspects connected with the Bahraini on whose computer the Mubtakkar was discovered were going nowhere. The U.S. would have to look elsewhere.

Conventional wisdom has long held that the U.S. has no human intelligence assets inside al Qaeda. "That is not true," writes Suskind. Over the previous six months, U.S. agents had been receiving accurate tips from a man the writer identifies simply as "Ali," a management-level al-Qaeda operative who believed his leaders had erred in attacking the U.S. directly. "The group was now dispersed," writes Suskind. "A few of its leaders and many foot soldiers were captured or dead. As with any organization, time passed and second-guessing began."

And when asked about the Mubtakkar and the names of the men arrested in Saudi Arabia, Ali was aware of the plot. He identified the key man as Bin Laden's top operative on the Arabian Peninsula, Yusuf al Ayeri, a.k.a. "Swift Sword," who had been released days earlier by Saudi authorities, unaware that al-Ayeri was bin Laden's point man in the kingdom.

Ali revealed that Ayeri had visited Ayman Zawahiri in January 2003, to inform him of a plot to attack the New York City subway system using cyanide gas. Several mubtakkars were to be placed in subway cars and other strategic locations. This was not simply a proposal; the plot was well under way. In fact, zero-hour was only 45 days away. But then, for reasons still debated by U.S. intelligence officials, Zawahiri called off the attack. "Ali did not know the precise explanation why. He just knew that Zawahiri had called them off."

The news left administration officials gathered in the White House with more questions than answers. Why was Ali cooperating? Why had Zawahiri called off the strike? Were the operatives planning to carry out the attack still in New York? "The CIA analysts attempted answers. Many of the questions were simply unanswerable."

One man who could answer them was al-Ayeri - but he was killed in a gun battle between Saudi security forces and al Qaeda militants, who had launched a mini insurrection to coincide with the U.S. invasion of Iraq. Suskind quotes a CIA operative as questioning whether it was an accident that the Saudis had killed the kingpin who could expose a cell planning a chemical weapons attack inside the U.S. "The Saudis just shrugged," the source tells Suskind. "They said their people got a little overzealous." .S. intelligence got its first inkling of the plot from the contents of a laptop computer belonging to a Bahraini jihadist captured in Saudi Arabia early in 2003. It contained plans for a gas-dispersal system dubbed "the mubtakkar" (Arabic for inventive). Fearing that al-Qaeda's engineers had achieved the holy grail of terror R&D - a device to effectively distribute hydrogen-cyanide gas, which is deadly when inhaled - the CIA immediately set about building a prototype based on the captured design, which comprised two separate chambers for sodium cyanide and a stable source of hydrogen, such as hydrochloric acid. A seal between the two could be broken by a remote trigger, producing the gas for dispersal. The prototype confirmed their worst fears: "In the world of terrorist weaponry," writes Suskind, "this was the equivalent of splitting the atom. Obtain a few widely available chemicals, and you could construct it with a trip to Home Depot - and then kill everyone in the store."

The device was shown to President Bush and Vice President Cheney the following morning, prompting the President to order that alerts be sent through all levels of the U.S. government. Easily constructed and concealed, mass casualties were inevitable if it could be triggered in any enclosed public space.

Having discovered the device, exposing the plot in which it might be used became a matter of extreme urgency. Although the Saudis were cooperating more than ever before in efforts to track down al-Qaeda operatives in the kingdom, the interrogations of suspects connected with the Bahraini on whose computer the Mubtakkar was discovered were going nowhere. The U.S. would have to look elsewhere.

Conventional wisdom has long held that the U.S. has no human intelligence assets inside al Qaeda. "That is not true," writes Suskind. Over the previous six months, U.S. agents had been receiving accurate tips from a man the writer identifies simply as "Ali," a management-level al-Qaeda operative who believed his leaders had erred in attacking the U.S. directly. "The group was now dispersed," writes Suskind. "A few of its leaders and many foot soldiers were captured or dead. As with any organization, time passed and second-guessing began."

And when asked about the Mubtakkar and the names of the men arrested in Saudi Arabia, Ali was aware of the plot. He identified the key man as Bin Laden's top operative on the Arabian Peninsula, Yusuf al Ayeri, a.k.a. "Swift Sword," who had been released days earlier by Saudi authorities, unaware that al-Ayeri was bin Laden's point man in the kingdom.

Ali revealed that Ayeri had visited Ayman Zawahiri in January 2003, to inform him of a plot to attack the New York City subway system using cyanide gas. Several mubtakkars were to be placed in subway cars and other strategic locations. This was not simply a proposal; the plot was well under way. In fact, zero-hour was only 45 days away. But then, for reasons still debated by U.S. intelligence officials, Zawahiri called off the attack. "Ali did not know the precise explanation why. He just knew that Zawahiri had called them off."

The news left administration officials gathered in the White House with more questions than answers. Why was Ali cooperating? Why had Zawahiri called off the strike? Were the operatives planning to carry out the attack still in New York? "The CIA analysts attempted answers. Many of the questions were simply unanswerable."

One man who could answer them was al-Ayeri - but he was killed in a gun battle between Saudi security forces and al Qaeda militants, who had launched a mini insurrection to coincide with the U.S. invasion of Iraq. Suskind quotes a CIA operative as questioning whether it was an accident that the Saudis had killed the kingpin who could expose a cell planning a chemical weapons attack inside the U.S. "The Saudis just shrugged," the source tells Suskind. "They said their people got a little overzealous."

Authorities did not describe Howards' behavior in any further detail.

While Howards was released later in the evening, officials are reviewing possible federal charges. His age and hometown were not listed. There was no phone number listed for him in the local phone book.

Cheney is attending the AEI World Forum conference in the Vail Valley, an unofficial summit, created and hosted by former president Gerald R. Ford. Former world leaders, current government officials, scholars and business leaders from around the world are invited to discuss important global issues, organizers say.

The plan caused particular alarm among US officials because it used a device known as a mubtakkar, meaning "initiative" or "invention". The device, the size of a tin of paint, could be easily concealed and would allow the remote release of the deadly gas.

Suskind describes the panic in the higher echelons of the US government on learning of the plan. He quotes President George Bush as voicing concern about the group's motives for calling off the attack. "I mean, this is bad enough. What does calling this off say about what else they're planning?" Mr Bush asked, according to Suskind. "What could be the bigger operation Zawahiri didn't want to mess up?"

Suskind speculates that the attack was called off because it would not be sufficiently destructive or eye-catching, even though it supposed thousands of deaths and widespread panic in New York.

"Al-Qaida's thinking is that a second-wave attack should be more destructive and more disruptive than 9/11," the author said in an interview with Time magazine, which published an extract from the forthcoming book.

"That would create an upward arc of terror and anticipation between the second and ostensibly a third attack. That fear and terror is a central goal of the al-Qaida strategy."

The planned subway attack echoes the release of sarin in the Tokyo subway in 1995, which killed 12 people.

In Chicago, attorneys for Sami Latchin, a man accused of serving as a "sleeper agent" in the United States for Saddam Hussein's regime, have asked a federal judge whether the National Security Agency eavesdropped on his telephone conversations. Prosecutors say a representative of the Justice Department in Washington will answer the question -- but only in the judge's chambers with defense attorneys not allowed.

Such secret procedures, once rare in American courts, have become more common since the Sept. 11 terrorist attacks. Prosecutors say they need secrecy to protect undercover agents, informants, and witnesses from reprisals and to keep critical information pipelines from being shut down.

But defense attorneys say the right of defendants to confront their accusers, guaranteed by the Sixth Amendment to the Constitution, is being worn away under the guise of national security.

"It's critical to the functioning of a healthy democracy that people know what the government is doing in their name," said David Cole, a professor at the Georgetown University Law Center.

But former federal prosecutor Andrew McCarthy, who sent the blind Egyptian sheik Omar Abdel-Rahman to prison for plotting to blow up New York landmarks, scoffed at the notion that the public has a right to know what is going on in terrorism investigations.

"In point of fact, the public doesn't have a right to know a large variety of information maintained by the government, particularly its investigators, its intelligence services, and that presumption doesn't change just because someone is charged with a crime," McCarthy said.

Ex parte hearings -- from which one side is barred -- are legal under the Classified Information Procedures Act, passed three decades ago to combat "graymail," in which defendants charged with spying would try to force the government to drop the charges by threatening to expose US secrets. But Critics say the law is now being overused.

The Louisiana ban would take effect if Roe v. Wade is overturned. Medicaid, which provides health benefits for the poor and disabled, requires funding for abortions in cases of rape or incest. Louisiana would allow those exceptions so long as it was required for Medicaid funding.

Seven states have such abortion trigger laws, and Louisiana already had a trigger law, although abortion legislation has been blocked by courts. The new law would mean the ban would happen quicker in the case of a new Supreme Court decision.

Blanco cited "overwhelming" support for the bill in the state Legislature.

"The central provision of the bill supports and reflects my personal beliefs," she said in a statement, adding she had hoped for legislation with exceptions for rape and incest.

Planned Parenthood President Cecile Richards said lawmakers were focused on the wrong thing, especially as the state rebuilds from Hurricane Katrina, which devastated New Orleans last August.

"It is hard to believe that by passing this ban they are addressing what is most on the minds of most of the citizens of Louisiana," she told Reuters.

Most U.S. states have some limits on abortion linked to gestation of the fetus and often based on viability, essentially the ability to live outside the womb.