Nearly 40 people have been arrested on suspicion of attempted murder after a "minor argument" in a shop ended in a man being chased down and stabbed.
A man in his 30s was left fighting for his life in hospital after the incident in Fulham Palace Road, Hammersmith, in west London, in the early hours of Monday morning.
The Metropolitan Police said the victim was chased by a group of men and women from a nearby shop where the altercation began, while two knives were found close to the scene.
Officers arrested 39 people at a property near the scene after failing to cooperate with police. They were taken into custody at several police stations.
The force was called to reports of a stabbing in the street shortly before 1am.
Superintendent Mark Lawrence, said: "What appears to have been a minor argument has resulted in a man sustaining life-threatening injuries.
"Officers were quickly on the scene and provided him with first aid prior to the arrival of our colleagues in the LAS.
"He has been taken to hospital where he continues to receive treatment for his injuries.
"Whilst it is unusual for so many people to be arrested in the early stages of an investigation such as this, due to a lack of co-operation and the necessity of securing essential evidence following a serious assault, this action was appropriate."
Neighbours of the flat in Greyhound Road, where the arrests are believed to have been made, said a group of people outside at about 11pm on Sunday, while others could be seen in a first floor window.
One woman said they were in their late teens or early 20s and the atmosphere appeared to be "quite relaxed and chilled".
"We just heard normal talking. It sounded like squealing girls like you get on a night out," she said.
Her friend, who is visiting London for New Year's Eve, saw police in the street after the stabbing.
"It was a bit mad," he said. "I woke up about 3am and there was about 25 police officers down here and about 30 or so people - some handcuffed, some weren't handcuffed.
"More people came out of there (the flat) and more police went in there.
"At about 5am, the forensics turned up."
On Monday morning, a pool of blood could be seen on the pavement outside a branch of Sainsbury's around the corner in Fulham Palace Road.