Ordinary Londoners demonstrated “breath-taking heroism” in disarming a knife-wielding attacker who injured several people in Friday’s incident at London Bridge, mayor Sadiq Khan said.

Police shot dead the man who had strapped a fake bomb to his body and stabbed a number of people in what they said was a terrorism incident.

Videos on social media showed a crowd of people who had tackled the man to the ground, before being ushered away by police who then shot him.

“What’s remarkable about the images we’ve seen is the breath-taking heroism of members of the public who literally ran towards danger not knowing what confronted them,” Khan told reporters.

“Members of the public didn’t realise at the time that was a hoax device, and they really are the best of us,” he added.

In the videos, a man can be seen retrieving a knife from the huddle on the ground before urging bystanders to get away.

George Robarts, a translator who was on the bridge at the time, said the unidentified man had run through traffic and jumped the central partition to tackle the attacker with several people.

“We ran away but looks like he disarmed him,” he said in a Tweet. “Amazing bravery.”

Rob Underwood, a 65-year-old from Lincolnshire, eastern England, who was visiting London for the day, said he heard bangs that sounded like a firecracker going off and did not initially realise they were gunshots.

“Once you see everybody rushing and scattering, you (are) really fearing for your own safety and I think the major thing was just to get out of the way and get down,” he said.

“You just feel very scared, very anxious about what’s happening and just wait for whatever is going to pass.”