LONDON, Aug. 4 -- Al Qaeda's second-in-command said in a video statement Thursday that the London transit bombings were retribution for British military intervention in Muslim countries and warned of "more destruction" if Britain doesn't withdraw. He also threatened new attacks on Americans.

The statement from Ayman Zawahiri was issued on a day in which London commuters rode trains and buses amid some of the tightest security since World War II, due to fears of a repeat of the attacks of July 7 and 21. No attack occurred. Instead, the four-week anniversary of the July 7 explosions brought the first statement clearly from al Qaeda about the violence.

Prime Minister Tony Blair "has brought you destruction in central London and, God willing, will bring more destruction," Zawahiri said, addressing the "English people" in a statement broadcast on the al-Jazeera satellite television channel.

"Our message to you is crystal clear: Your salvation will only come in your withdrawal from our land, in stopping the robbing of our oil and resources, and in stopping your support for the corrupt and corrupting leaders."

Officials at the prime minister's Downing Street office provided no comment. Blair has previously rejected claims that the transit bombings were a result of Britain's role in the

Iraq war, and politicians across the spectrum have stood by him.

This is exactly why I think its so silly for our leaders to try and claim that the London attacks had nothing to do with Iraq. As I've said before, they very much have something to do with Iraq. Iraq is part of the war on terrorism. The London bombings were acts of terrorism carried out by people sharing a loose affiliation with Zarqawi and the other monsters we're fighting there.

The London bombings were a method by which the terrorists hope to deter one of America's staunchest allies in Iraq, which is exactly why pulling out of Iraq is not the proper course of action in response to the attacks. Because we should never, ever be in the habit of doing what the terrorists want us to do.