A videotape of one of the men responsible for the London bombings on 7 July, Mohammad Sidique Khan, has been aired on al-Jazeera television.
Muslim leaders, politicians and victims' families have been giving their reactions.
JOHN TAYLOR, FATHER OF BOMB VICTIM CARRIE TAYLOR
I wasn't surprised by it - it just goes to show how totally evil these people are.
I believe it was a pre-planned event. We're in a war situation now and this has been coming for a very long time.
It wasn't a one-off event where four guys just go together and planned to show the world what they could do.
I believe there was a more sinister thing behind this.
Dr AZZAM TAMIMI, MUSLIM ASSOCIATION OF BRITAIN
If the tape is genuine, and they appear genuine, then this proves what we have been saying all along.
The involvement of Britain in the war in Iraq has provided Osama Bin Laden with extra ammunition to recruit these young Britons and brainwash them.
Dr Tamimi said he found Khan's words "horrific".
He [Khan] seems totally convinced that he ought to punish the British people indiscriminately because of their contribution to electing the government.
He doesn't take into consideration that the majority of people were against the war.
SHAHID MALIK, LABOUR MP, DEWSBURY
Mr Malik, a Muslim who represents the constituency where Khan
lived, said he was "shocked and disturbed" by the video.
Khan accuses 'Westerners' of being responsible for the London bombings but we must be clear that the only people responsible for these heinous acts were him and his twisted associates.
The MP also criticised British Muslims who maintained Khan and his accomplices were not responsible for the 7 July bombings due to "rampant conspiracy theories within the community".
Far too many Muslims have been living in a state of denial but now they have heard it from the horse's mouth and must come to terms with the undoubted challenge that this presents.
We must not allow the evil few to hijack issues such as Palestine or Kashmir or Iraq. Defending just causes with evil acts serves only to malign those causes.
The large scale indiscriminate killing of innocents can never be a viable solution and those that believe otherwise must know that they will feel the full brunt of the law in this country.
INAYAT BUNGLAWALA, MUSLIM COUNCIL OF BRITAIN
Mr 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.
Holding all British people responsible for the Iraq war is just plain wrong - this country was bitterly divided and many millions, perhaps the majority, clearly opposed the war.
Mr Khan has allowed his hatred to distort his moral compass.
However, this tape does serve to confirm that the war in Iraq and our policies in the Middle East have indeed led to a radicalisation amongst a section of Muslim youth.
DAVID DAVIS, SHADOW HOME SECRETARY
Nothing can justify the murder of innocent people. People across Britain will be sickened by this video.
MARK OATEN, LIBERAL DEMOCRAT HOME AFFAIRS SPOKESMAN
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.
VERONICA CASSIDY, MOTHER OF BOMB VICTIM CIARAN CASSIDY
I don't think of these people. It's not going to
bring my son back.
SADIQ KHAN, LABOUR MP, TOOTING, SOUTH LONDON
Mr Khan, who is a Muslim, said if the video was authentic, it was "despicable".
It will send a shiver down the spine of all law-abiding and peaceful
This confirms how evil these people are. We mustn't allow these monstrous words to divide what is a united nation.
I think it's clear that these tapes are released at times to maximise
publicity and spread discord.
What I hope we would not do is give too much airtime to the views of murderers.
CHRIS ADWU, COUSIN OF BOMB VICTIM OJARA IKEAGWU
Mr Adwu said it was no surprise al-Qaeda was claiming responsibility for the attacks, adding he did not think it was necessarily in the public interest to air the tape in the UK.
I personally don't share the view that freedom of speech should be extended that far, it just gives them further publicity.
Having said that, technology has moved on and it's difficult to control the flow of information from one country to another.
MASSOUD SHADJAREH, ISLAMIC HUMAN RIGHTS COMMISSION
There is no justification for threats to and murder of the innocent, as were evidenced in tonight's broadcasts.
The repeated citation of the wars in Iraq and elsewhere as the reason for the 7/7 attacks and possible further attacks, simply highlights that the government is in denial about the effect of their illegal and immoral policies on the security of the UK.
ERIC JOYCE, LABOUR MP
The vulnerable people in question of which Mohammad Sidique Khan is one will be sometimes recruited using different arguments.
In previous years it may have been Palestine or Kashmir, in this case the proselytisers
have used Iraq.
History I hope will show that the action in Iraq was the right thing.