Williams called on all faiths to speak out against violence committed by religious fanatics. 'When the Christian, the Muslim or the Jew sees his neighbour of another faith following the ways of this world instead of the peaceful will of God, he must remind his neighbour of the nature of the one God we look to.'

The archbishop's address came as the Prime Minister's former envoy to Iraq acknowledged that the invasion of Iraq had played into al-Qaeda's hands. Sir Jeremy Greenstock, who as UK ambassador to the United Nations was at the centre of events in the run-up to the war, said the allies in Iraq had 'suffered the consequences' of al-Qaeda's determination to exploit the opportunities presented by a war on Arab soil.

He told Radio Four's Today programme yesterday that the West could not defeat Osama bin Laden's terror network by military means alone, but must adopt policies to reduce resentment in the Muslim world. 'I think it was one of the objectives of Osama bin Laden and the al-Qaeda leadership originally to draw America into conflict on Arab soil as close to Saudi Arabia as possible.

'Iraq is not yet a failed state. We are in a transition period, which has got considerable difficulties. But if Iraq ends up as a failed state and we leave it in that state, then we are worse off than when we started,' Greenstock warned.

A number of British Muslim groups used the anniversary to warn that 9/11 had led to a rise in Islamophobia. Massoud Shadjareh, chairman of the Islamic Human Rights Commission, said: 'The backlash against Muslims in the UK needs systematic and sustained responses from the British government, yet instead we see endless attention given to increasing draconian legislative measures which are used almost overwhelmingly against Muslims.'

Radical Muslim group al-Muhajiroun held a conference at which the group's UK leader, Anjem Choudary, praised the 'Magnificent 19' hijackers.

He said of bin Laden: 'He is my fellow Muslim brother. We believe in the same God, we believe in the same messenger ... whether he is an oppressor or oppressed.

'I do not believe he is an oppressor, he is on the right path. If you had an election in any Muslim country, he would win.'

In the United States, President Bush marked the anniversary by linking the events of 9/11 to the war in Iraq. 'America was attacked with deliberate and massive cruelty. We remember the tragedy of that day. We remember the images of fire, and the final calls of love, and the courage of rescuers who saw death and did not flee,' Bush said in a radio address. 'Since that day, our nation has waged a relentless war against terror and evil. We pray for the brave men and women of the United States armed forces who are serving our country on the front lines of this war.'

In New York, hundreds of British police officers joined counterparts from 47 national forces to form an honour guard for the families of those who died in the atrocities.

At the British Memorial Garden in the city, 67 police officers represented each of the Britons who died, while the North American Welsh Choir paid a choral tribute.

Yesterday also marked the deadline for lawsuits related to the terrorist attacks, prompting a last-minute flurry of filings. Officials at the Port Authority of New York and New Jersey, the owner of the World Trade Centre, filed a suit for damages against Saudi Arabia, alleging that its royal family had supported al-Qaeda in the years before 9/11.

The claim followed a similar suit by Cantor Fitzgerald, the brokerage firm that lost 658 employees in the attacks.

END