One of the four suicide bombers behind the 7 July London Tube attacks which killed 52 people has appeared in a tape obtained by an Arab TV station.
In the message recorded before he died, and broadcast on al-Jazeera, Mohammad Sidique Khan said he was “a soldier”.
Khan, 30, said the UK government had committed atrocities against Muslims and he was inspired by Osama Bin Laden.
In a second video, al-Qaeda’s Ayman al-Zawahri claimed responsibility for the blasts and threatened new attacks.
Public blamed
The eldest of the four bombers, Khan, who came from Dewsbury in West Yorkshire, was responsible for the Edgware Road Circle Line explosion which killed six people and injured 120.
It is not clear when or where either tape was filmed, or whether Khan was aware the interview with al-Zawahri - al-Qaeda’s second in command - would be edited onto the same tape, said BBC home affairs correspondent Margaret Gilmore.
Prime Minister Tony Blair was not commenting on the tape, said BBC political editor Nick Robinson. The Foreign Office has also said it will not respond.
We are at war and I am a soldier - now you too will taste the reality of this situation
Mohammad Sidique Khan
On the tape the bomber says in a Yorkshire accent: "Our words are dead until we give them life with our blood.
“I and thousands like me have forsaken everything for what we believe.”
He said the public was responsible for the atrocities perpetuated against his “people” across the world because they supported democratically elected governments who carried them out.
“Until we feel security, you will be our targets,” he said.
"Until you stop the bombing, gassing, imprisonment and torture of my people we will not stop this fight.
“We are at war and I am a soldier. Now you too will taste the reality of this situation.”
‘Enemy’s land’
In a separate recording, al-Zawahri said the Tube attacks were a “slap” to the policies of Tony Blair.
Scotland Yard has confirmed it is aware of the tape.
BBC security correspondent Gordon Corera said it was being examined closely for any clues on the 7 July attacks, in which three Tube trains and a bus were bombed.
Counter-terrorism sources said they were not treating the messages as conclusive proof that the al-Qaeda leadership directly ordered - rather than simply inspired - the attacks, he said.
I talk to you today about the blessed London battle which came as a slap to the face of the tyrannical, crusader British arrogance
Ayman al-Zawahri
The video was likely to be viewed as part of the information and propaganda war waged by al-Qaeda, with its focus on blaming attacks on Western foreign policy and warning of more to come, added our correspondent.
In the al-Zawahri tape he said, speaking in Arabic, that the bombings were proof al-Qaeda had moved the battle to “the enemies’ land”.
He said: "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.
“This blessed battle has transferred - like its glorious predecessors in New York, Washington, and Madrid - the battle to the enemies’ land,” he said.
He added they would target the “lands and interests of the countries which took part in the aggression against Palestine, Iraq and Afghanistan”.
‘Brainwashing’
Nick Robinson said the London bomber tape would “chill people to the marrow”.
“To hear a fellow countryman in the familiar accent of North Yorkshire - a man who gave much of his life to teaching under-privileged children - say ever so calmly ‘This is why I am a soldier in the name of Islam, this is why I regard you all as legitimate targets in my war’, will shock and horrify people.”
Muslim Council of Britain spokesman Inayat Bunglawala said it was “obscene” to suggest justice for the people of Iraq could be obtained by committing an act of injustice against the people of London.
It’s all brainwashing by some wacko scholar who believes his own version of the Koran - there is no holy war
Gous Ali, boyfriend of bomb victim
"There is never an excuse for acts of terrorism against innocent civilians.
“However, this tape does serve to confirm that the war in Iraq has indeed led to the radicalisation amongst a section of Muslim youth.”
He said the bombings were a “crime against the Islamic faith”.
The Muslim boyfriend of one of the bomb victims condemned the terrorists’ broadcasts as “wrong and all lies”.
Gous Ali’s girlfriend Neetu Jain, a Hindu, was killed in the explosion on the No 30 bus in Tavistock Square.
Mr Ali, who has studied Islam, said: "I just want to go on national television myself and expose their lies.
"It’s all brainwashing by some wacko scholar who believes his own version of the Koran and has made it his own battle. There is no holy war.
“They have so much coverage it’s damaging, yet the voices of the innocent victims are not being heard.”