London mayor to attackers: 'You do not commit these disgusting acts in my name' Seven were killed and dozens were injured in the Saturday attack.

 -- At a vigil for those killed and injured by terrorists in London this weekend, the city's mayor said in a message to the attackers, "As a proud and patriotic British Muslim ... you do not commit these disgusting acts in my name."

Sadiq Khan, London's first Muslim mayor, said to the crowd today, "London stands in defiance against this cowardly attack on our city, our people, our values and our way of life. As the mayor of London, I want to send a clear message to the sick and evil extremists who commit these hideous crimes: we will defeat you. You will not win."

"Your perverse, disgusting ideology has nothing to do with the true values of Islam. And you will never succeed in dividing our city," Khan added.

Farhad Ahmad, a British imam, told ABC News today, "We were shocked just as everybody was and we were pained."

"Also we knew that a lot of people would have questions like, 'Is this really the teachings of Islam?' So we wanted to come. A lot of us are wearing shirts that say, 'I'm Muslim ask me anything.' Mine says 'Muslims for humanity,'" Ahmad said. "We wanted to show our solidarity but also let people know that Islam is a message of peace. ... The true teachings of Islam are not represented by these people."

Ahmad said he has seen some positive outreach since the terror attacks, telling ABC News that earlier today a van pulled over, a man got out of the car and hugged him.

"That is London," he said.

Khan said at the vigil, "Our city is filled with great sorrow and anger tonight but also great resolve. ... This is our city. These are our values and this is our way of life. London will never be broken by terrorism. ... We will defeat the terrorists."

"Today we mourn the loss of innocent lives, Londoners and people from around the world. We send our love to the victims' families and to all those who are injured," Khan said.

A minute of silence was held at the vigil today and Khan said visitors were welcome to lay tributes.

Seven victims were killed and dozens were injured Saturday night in what Khan called a "barbaric" attack. Officials said assailants used a vehicle to plow into pedestrians on London Bridge and then drove to Borough Market, where people were attacked with knives. Three suspects were shot and killed in the wake of the carnage and all were wearing fake suicide belts, police said.

ABC News' James Longman contributed to this report.