LONDON — Britons paused in silence and walked in solidarity today to mark the 10th anniversary of suicide bomb attacks on London’s transit system.

Four British men inspired by al-Qaida blew themselves up on three London subway trains and a bus during the morning rush hour on July 7, 2005, killing 52 commuters and injuring more than 700. The memory of that morning remains raw in this country of 64 million.

Solemn ceremonies were held throughout the capital, starting at the memorial in London’s Hyde Park devoted to the victims. Prime Minister David Cameron and London Mayor Boris Johnson weaved through the memorial’s 52 pillars to lay wreaths, one for each victim.

At 8:50 a.m., the moment the attacks began, the park fell silent. Families of victims clutched flowers. Some in the crowd bowed their heads.

Sajda Mughal, a survivor, said even after 10 years, the anniversary remains “emotional.”

Johnson said the attack was a terrible shock to the capital but it was important to remember it.

“The people who are trying to attack the city basically failed,” he told The Associated Press.

The attack occurred two years after Britain took part in the U.S.-led invasion of Iraq. But former Prime Minister Tony Blair, the nation’s leader at the time of the bombings, said Tuesday that terrorism was “a global problem” that affected countries regardless of their involvement in the war in Iraq.

Across the city, survivors, transport staff and emergency workers laid flowers at the sites of the four bombings. Some Londoners heeded a call to walk part of the way to work in memory of the day 10 years ago when the city’s transit network stopped.

Cameron said the slayings last month of 30 British tourists in Tunisia was a reminder that terrorist threats remain real and deadly.