A man has been arrested after armed police responded to two people being stabbed in Kensington, Scotland Yard said.
Firearms officers descended on Derry Street in central London at about 11am on Friday and were seen outside a building that houses Sony’s London headquarters.
The Metropolitan Police said two people suffered stab injuries, but they are not believed to be in life-threatening conditions.
It is not being treated as “terror related”, police said.
Footage filmed from an office opposite showed a number of armed police entering the building through the front door.
Trish Ellis, a personal assistant at the Mail on Sunday who witnessed the incident, said: “It started opposite our building in Derry Street, usual sirens and racket but then we heard shouting, and more and more sirens.
“A few people came out, then armed police were going in six-plus at a time, and more and more of them, but they seemed to be keeping people in the building.
“Gradually they started to release people in tens, twenties, and a stretcher turned up with all the medical kit on it, but just stayed outside.”
According to the Evening Standard, which its based by the scene, a witness reported seeing panicked people running from the incident while screaming.
“Large crowds of people began exiting the building’s front door at around 11 o’clock,” the onlooker said.
“Most were running, all towards Kensington Square Garden. Several were visibly panicked and some were screaming.”
A London Ambulance Service spokeswoman said one patient was taken to hospital, the other to a “major trauma centre”.
Scotland Yard said: “Officers, including firearms officers, and London Ambulance Service are in attendance.
“Evacuations have taken place as a precaution. One person has been arrested.”