This city fell silent for two minutes Friday in a tribute to the 52 people killed a year ago at the hands of four suicide bombers. Cathedral bells tolled, candles were lighted and flowers were laid at the subway stations and London square where three trains and a bus were blown apart last July 7.
The anniversary was an opportunity for "the whole nation to come together," Prime Minister Tony Blair said.
He called it a chance "to offer comfort and support to those who lost loved ones or were injured on that terrible day."
Metropolitan Police Commissioner Ian Blair warned London to expect more violence.
"I know there will be further attacks, but as to whether we will stop those, well, we've stopped three already," he told BBC television.
The day of remembrance began at King's Cross station at 8:50 a.m., the moment when four young men detonated their bomb-laden backpacks during the morning rush hour. While a single bell tolled at St. Paul's, the city's main cathedral, Culture Secretary Tessa Jowell, London Mayor Ken Livingstone and London transportation chief Peter Hendy laid wreaths in a memorial garden outside the station.
At noon, the country fell silent for two minutes. Londoners streamed from their offices to gather on the streets and the steps of St Paul's.
Prime Minister Blair stood with members of the London Fire Brigade. The tennis matches at Wimbledon stopped. Passersby paused to read messages on the bouquets piled up at the bombing sites.
The ceremonies ended with an evening Mass in Regent's Park.
In Nottingham, outside an Islamic school, pupils came out with placards against terrorism. In the Yorkshire region, which was home to the bombers, Muslims gathered in parks to proclaim their stand against terrorism.
"This is a time when our country unites across all races, religions and divides and stands in solidarity with all those who have suffered so much in sympathy with them and in defense of the values we share," Blair said.
In the last year, however, reconciliation and understanding have eluded many in Britain.
A survey conducted by Populus and published Tuesday in the daily Times of London said that more than one in 10 British Muslims thought the London bombers should be regarded as "martyrs."
An additional 16% -- or 150,000 people -- said that although the attacks may have been wrong, the cause was right.
Two percent said they would be proud if a family member joined Al Qaeda, and 16% said they would be indifferent.
A video clip of one of the bombers, Shahzad Tanweer, that was released on an Islamist website and broadcast by Al Jazeera television Thursday, has compounded Britons' anxiety. In it, Tanweer says in his northern English accent, "What you have witnessed now is only the beginning of a string of attacks that will continue and become stronger."
The violence will continue "until you pull your forces out of Afghanistan and Iraq," he said.
The tape included a statement from Al Qaeda's second-in-command, Ayman Zawahiri, suggesting that the network had helped direct the bombings, and that deepened fears that the alienation felt by some British Muslims is being exploited by international militant groups.
Yet the poll also showed that most British Muslims want the government to take tougher measures against extremists in their communities. It found that 65% wanted more integration into mainstream British life, and that 35% would be proud if a family member joined the police force.
The peaceable Muslim majority has borne rising violence in the last year.
The Islamic Human Rights Commission complained at the end of last July that attacks on Asians had risen more than thirteenfold since the bombings. By July 28, nine mosques had also been attacked.
Despite promises of consensus from politicians and religious leaders immediately after the bombings, Blair's government has since been caught up in acrimonious wrangles with opposition parties, Muslim leaders, police, security services and the legal establishment over how best to fight terrorism.
The prime minister this week berated moderate Muslims for not doing enough to challenge extremists in their communities, insisting that was not a job for the government.
"You cannot defeat extremism through what a government does. You can only defeat it within a community," he said.
The opposition Conservative and Liberal Democrat parties objected last summer when Blair tried to push through much stricter anti-terrorism legislation than they had agreed to. They said Blair was moving away from Britain's traditional commitment to the rule of law.
Although watered down during months of rancorous debate, the controversial Terrorism Act 2006, which gives police the right to hold terrorism suspects for 28 days without charge, became law.
Janet Stobart of The Times' London Bureau contributed to this report.