Al Qaeda's No. 2 Blames Blair, Issues Warning

Christopher Blanchard, an analyst who has closely followed al Qaeda's public statements at the Congressional Research Service, called the tape an example of "pragmatic messianism" by Zawahiri. "Al Qaeda's fractured leadership apparently continues to believe that it can undermine support for current U.S. policies by directly addressing and threatening the American people," he said.

The first person to be charged in the bombings was ordered by a London judge Thursday to be held in custody until a hearing on Aug. 11. Ismael Abdurahman, 23, is charged with withholding information from police about one of the suspects in the July 21 attacks.

On Thursday, police charged two London sisters with similar offenses.

In New York on Wednesday evening, Police Commissioner Raymond Kelly told a gathering of business leaders that the bombs were made of easily obtained ingredients, the Associated Press reported. "It's . . . like these terrorists went to a hardware store or some beauty supply store," Kelly said.

Kelly said the bombers transported the bombs in beverage coolers to keep them from degrading, and that the bombs were probably detonated by cell phone alarms. Kelly said the information came from New York detectives who went to London to monitor the investigation.

London police were on extremely high alert Thursday, fearing that other bombers might follow an established pattern. The July 21 attacks occurred exactly two weeks after the July 7 bombings, and Thursday was two weeks after the second attack. Police were stationed at most subway entrances around the city, and public address systems on subway cars repeatedly warned passengers to be vigilant and report suspicious packages or people.

Thursday also marked the first time London's subway was operating at full capacity since the first bombs exploded during morning rush hour on July 7.

In interviews, many subway riders said they were not afraid. "You're more likely to get run over by a bus than to be killed in a terror attack," said Rob Parker, 36, a management consultant catching a train at the St. James's Park subway station. He said the al Qaeda tape was worrisome, but he would not alter his commuting routine because of it.

He did not hold the British government responsible for provoking the violence. "At the end of the day, we're a democracy and we voted to put people in office and make decisions," Parker said. "No one has a crystal ball. I thought that the Iraq war was the right thing to do."

London pollster and political analyst Stephen Shakespeare said the al Qaeda warning would probably boost Blair's political standing, which has already been helped by the government's firm, organized response to the bombings and a wave of national solidarity in the face of attack. The message will undermine critics who say he has overstated the threat, Shakespeare said.

The potential effect on Britain's 1.6 million Muslims is less clear. Shakespeare said his organization's recent polls show that while most feel loyal to Britain, about a third of Muslims polled feel a "divided loyalty" and 5 or 6 percent support the bombings.

Inayat Bunglawala, spokesman for the Muslim Council of Britain, a coalition of moderate Muslim groups, said the tape was probably intended to "incite others to go from being disaffected to taking up bombs."

"But I don't think it will contribute to that," he said. "What will contribute is the policies our country has been engaged in. We have always viewed Iraq as a disaster area for our country. . . . The solution is to remove the sources of anger among Muslim youth."

But Allaf, the Middle East specialist, said she believed the tape would add to the radicalization of Muslim youth in Britain. The most notable aspect of Zawahiri's address, she said, was that it was "logical and lucid" and would appeal to a wider audience than the rhetoric of "crazy mullahs."

Staff writers Susan B. Glasser in Washington and Dafna Linzer in New York contributed to this report.