Young Muslims and police gather on Westminster Bridge to pay tribute to attack victims The bridge was closed while thousands of people gathered there.

 LONDON -- Thousands of people gathered in London today to pay tribute to the victims of last week's attack.

Police officers, young Muslims and other Londoners with flowers in their hands walked across Westminster Bridge, where the attack took place exactly one week ago.

More than 500 young people from the Ahmadiyya Muslim Community in London were part of the ceremony, according to one of the organizers.

“When the attack happened we knew that a lot of people would have questions about whether this is actually what Islam teaches,” Farhad Ahmad, an imam with the Ahmadiyya Muslim Community, told ABC News.

He and other young Muslims on the bridge were wearing shirts that said “I’m a Muslim” on the front and “Ask me anything“ on the back.

“In this moment in time it’s very crucial that the Muslim community comes out and tells people what the true teachings of Islam are as compared to what people think Islam says based on some individuals’ actions," he said. "The Quran says that if you kill one person it’s like killing the whole of humanity. If we can get that true message of Islam across to people it will build bridges and bring communities together.”

On March 22, 52-year-old Khalid Masood, a Muslim convert with a criminal past, crashed his rented car into pedestrians on Westminster Bridge and later stabbed a police officer. Four people were killed in the attack, including the officer. Masood was shot and killed by police.