Metropolitan police confirm that officers were called to incident in Stoke Newington and a man was taken to hospital

A passenger disarmed an alleged knifeman on a bus in north London in scenes captured on video, in a week in which three young men died in stabbings in the capital.

The video, which has been circulating online, shows the two men near the front door of a 149 bus in Stoke Newington as an alarm siren blares. When one manages to seize the knife, the other sprints from the rear doors and makes off down the road.

As he watches his alleged assailant run off, the man shouts after him: “I’m an African. You’ll never take my life!”

The Metropolitan police said officers were called to Stoke Newington Road at 1.55pm on Tuesday to reports of a stabbing on a bus.

“Officers and London Ambulance Service attended and found a man in his 20s with minor lacerations to his hand and head,” a spokesperson for the force said. “He was taken to an East London hospital where he was treated for his injuries. He has now been discharged. There have been no arrests and enquiries continue.”

The incident took place during a violent start to the week in London, during which three young men were killed by knives in 24 hours. Abdullahi Tarabi, 19, and Syed Jamanoor Islam, 20, were killed on Tuesday afternoon; Rene Richardson, 24, died on Monday afternoon. The deaths, which occurred in different parts of the city, are not thought to be related.

The Met revealed on Wednesday that knife crime in London had risen by almost a quarter in a year, from 9,742 recorded incidents to 12,074. The Met suspects the increase is partly due to more people carrying a knife for self-protection.

In a briefing attended by the Guardian, Martin Hewitt, the force’s assistant commissioner, said: “Young people carrying knives are doing so for a variety of reasons including status, criminality and self-protection, but only around a quarter are affiliated with gangs.

“There is a phenomenon of people feeling that you need to carry a knife to be safe … The problem comes when you then get a confrontation.”