The purported number two man from Al Qaeda, Ayman al-Zawahiri, praised the July 7 bombings in London in a videotape that aired on Al-Jazeera. Osama bin Laden's right hand man appeared on the tape with a man whothat reportedly resembled one of the suicide bombers.

Al-Zawahiri allegedly described the rush-hour bombings on underground trains and a bus as a "slap for the policy" of British Prime Minister Tony Blair, the channel said.

Government officials from Britain and the United States said they were aware of the tape and were investigating it, but could not comment on its authenticity.

Speaking in English in a pronounced Yorkshire accent, the man that purportedlyresembled Mohammed Siddique Khan (the alleged leader of the July 7 London bombers) praised "our beloved sheik, Osama bin Laden," and declared, "We are at war, and I am a soldier and now you too will taste the reality of this situation."

Al-Zawahiri reportedly said that the attacks on three Tube trains and a bus were a “slap for the policy of British Prime Minister Tony Blair and these operations have taken the battle to the enemy’s lands”.

The New York Times reports that the video included what appeared to be a section (of tape)showing Al-Zawahiri speaking of "the blessed London battle, which came as a slap to the face of the tyrannical, crusader British arrogance."

"Like its glorious predecessors in New York, Washington, and Madrid, this blessed battle has transferred the battle to the enemies' land," Mr. Zawahiri said, speaking in Arabic.

The paper notes that the two men did not appear together on the tape.

The UK Times notes that the claims by al-Zawahiri are unusual. Al-Qaeda does not usually make direct claims of responsibility for terrorist operations, leaving it to sympathizers.

--Jim Roberts with wire reports.