Videotapes reveal al-Qa'ida's link to July 7 London bombings

In a flat West Yorkshire accent, Mohammed Sidique Khan declared: "Our words have no impact upon you, therefore I'm going to talk to you in a language that you understand. Our words are dead until we give them life with our blood."

In the video, which was broadcast by the Arabic television station al-Jazeera, Khan said: "Your democratically elected governments continuously perpetuate atrocities against my people and your support of them makes you directly responsible, just as I am directly responsible for protecting and avenging my Muslim brothers and sisters."

Khan, who worked as a learning mentor to children at a primary school in Beeston, Leeds, said: "Until we feel security, you will be our target. Until you stop the bombing, gassing, imprisonment and torture of my people, we will not stop this fight."

The video released by al-Jazeera, shows Ayman al-Zawahri, said to be Osama bin Laden's second-in-command, apparently confirming that al-Qa'ida was behind the attacks in the capital. The Egyptian claims the attacks were a "slap" to the policies of British Prime Minister Tony Blair. Speaking in Arabic, the Egyptian says the bombings are proof they have moved the battle to "the enemy's land".

He threatens more attacks in Europe and refers to a so-called offer of a truce with the West.

Last night Scotland Yard said it was "aware" of the broadcast but refused to comment on its authenticity. A spokesman said: "We are aware of the tape and it will be assessed as part of the investigation."

Downing Street refused to comment. But the tape was met with a wave of condemnation from political figures and leaders of the British Muslim community. David Davis, the Shadow Home Secretary, condemned the video. He said: "People across Britain will be sickened by this video. Nothing can justify the murder of innocent people".

Mark Oaten, the Liberal Democrat Home Affairs spokesman, added: "There can be no justification for the bombings that took place in London.

"Britain's involvement in the war in Iraq is no excuse for Muslim extremism.

"However, it would be wrong for the Government to deny that Muslim communities feel a sense of unease about our involvement in Iraq."

Khan, who lived with his wife and 14 month old daughter in Lees Holm, Leeds, died in the 7 July blasts along with fellow bombers Shezad Tanweer, Hasib Hussain and Germaine Lindsay. Khan killed six people and himself when he detonated a bomb on a Circle Line train at Edgware Road station.

The video, obviously heavily edited, shows 30 -year-old Khan wearing a dark green hooded top and red and white headscarf as he made the brief broadcast in front of a patterned cloth. He declared: "We are at war and I am a soldier. Now you too will taste the reality of this situation."

He said: "I and thousands like me are forsaking everything for what we believe. Our driving motivation doesn't come from tangible commodities that this world has to offer. Our religion is Islam, obedience to the one true God, Allah and follow in the footsteps of the final prophet and messenger Mohammed."

A spokesman for al-Jazeera said Khan was shown at a separate location and is not pictured with the al-Qa'ida second-in-command.

Al-Zawahri, who was dressed in a black turban and white robes, said: " Blair not only disregards the millions of people in Iraq and Afghanistan, but he does not care about you as he sends you to the inferno in Iraq and exposes you to death in your land because of his Crusader war against Islam ... I talk to you today about the blessed London battle which came as a slap to the face of the tyrannical, Crusader British arrogance. It's a sip from the glass that the Muslims have been drinking from."

The video comes after a group called "The Secret Organisation of al-Qa'ida in Europe" claimed responsibility for the attacks on a popular Islamic militant web site.