Britain's capital marks the first anniversary of the terror attack on its public transport system Friday. Four suicide bombers, all British Muslims, murdered 52 passengers when they detonated their bombs in underground train carriages and on one double-decker bus. The attack came a day after another momentous event for London: On July 6, 2005, the International Olympic Committee announced that the 2012 Olympics would take place in the city. Tens of thousands thronged Trafalgar Square to celebrate the victory over rival Paris. On Thursday, it seemed as if London was trying to cling to those moments of celebration instead of being forced to dwell on the atrocities of the following day - and their implications. The team preparing the 2012 Olympics convened another event in the square, but this time it was sparsely attended, mostly attracting tourists. London Mayor Ken Livingstone, who angered many shortly after the attacks by justifying suicide attacks in Israeli cities - saying that they were the only way the Palestinians could fight Israeli tanks - didn't even mention the London bombings in his speech. Instead, he spoke about the way sport could battle the problem of "obesity afflicting our nation and others in the Western world" and how "sport can unite all of mankind." Prime Minister Tony Blair and Culture Secretary Tessa Jowell mentioned the bombings only in passing, Blair saying that a "London of different backgrounds and different beliefs" was "determined to succeed" in the face of the bombings and the challenge of staging the Olympics. A permanent memorial for the 52 victims will eventually be built at the planned Olympic Park in east London. Behind the speaker's podium at Trafalgar Square stood a group of children who had served as "special ambassadors" during the Olympic bid, among them a headscarved Muslim girl who, as if by coincidence, had been placed in the middle of the frame, directly behind the politicians. Neither Blair nor Jowell referred to the challenge to Britain of a home-grown terror threat among the Muslim community, 13 percent of which, according to opinions polls this week, saw the London bombers as martyrs. Nor have more moderate Muslim leaders been willing to take responsibility for the radicalization of their community. Imam Dr. Abduljalil Sajid, chairman of the Muslim Council for Religious and Racial Harmony, said at a special interfaith service Thursday at Westminster Abbey that the bombings had been the actions of "a few evil-minded people." Sounding a different note was British Chief Rabbi Dr. Jonathan Sacks, who wrote in an article posted Thursday on the Internet that "every minority has a duty to honor the interests of the wider society of which it is a part." After the celebration in Trafalgar Square Livingstone and Jowell spoke at the opening of a Muslim cultural event, IslamExpo in Northern London. The organization behind the event bills itself as being "dedicated to enhancing understanding of Islam in Britain and building bridges between the Muslim world and the West." Meanwhile, television channels began airing new video footage, which had just appeared on Al-Jazeera television, of one of the suicide bombers. Shenzad Tanweer, who had blown himself up at Aldgate Station, said, "What you have witnessed now is only the beginning of a string of attacks that will continue and become stronger." Tanweer, who was born in Bradford, Yorkshire, visited Pakistan at the end of 2004 and returned to Britain a committed jihadist. The video released Thursday also contains a statement by al-Qaida leader Ayman Al-Zawahiri, Osama bin Laden's deputy, strengthening the theory that the London bombings were directed by al-Qaida. Friday's anniversary will be publicly marked in London by a series of events that will include unveiling of plaques at the underground stations and at Tavistock Square where the bombs went off, two minutes of silence at midday across Britain, services at churches near the sites of the blast and a central event in Regent's Park.