This is the dramatic moment police detained a man less than a mile from the queue for the Queen - after two officers were stabbed.
Footage shot by taxi driver Youssef Boucetta, 27, shows a man being pinned to the ground near Leicester Square at around 6am today (16/9).
The cabbie says one officer was heard "screaming 'I've been stabbed'" before he used his jacket to help.
The injured cops - a man and a woman - were taken to hospital although their injuries are not life-threatening, the Met said.
They were on patrol with colleagues in the area when they were made aware of a man in possession of a knife.
A man believed to be aged in his 20s has been arrested on suspicion of grievous bodily harm and assaulting an emergency services worker.
Youssef was on his way to pick up a passenger from Heathrow Airport when the incident took place in front of him.
He said: "I was there when the stabbings happened. It was very disturbing, especially seeing the female officer had been stabbed.
"I was just out on a job heading to pick someone up at Heathrow airport. First of all I saw this female officer appear from around the corner with blood on her arm.
"She was screaming 'I've been stabbed, I've been stabbed', so I quickly got out my car with my jacket and wrapped it around her.
"Then these two male officers came around the corner.
Filmed on 16th September 2022