A 20-year-old man has died and two others have been injured in a stabbing outside Parsons Green Tube station.
Police were called at 7.37pm on Monday to reports of an incident outside the Underground station, where 30 people were injured in a terror attack last month.
Scotland Yard said a murder investigation had been launched and one of the injured men had been arrested in connection with the incident.
The arrested man was taken to hospital and has since been discharged. He remains in custody, officers added.
The stabbing is not terror-related, Scotland Yard said.
The force said in a statement: “Police were called on Monday, 16 October at 19:37 hours following reports of three males stabbed outside Parsons Green Tube Station.
“Officers attended along with the London Ambulance Service (LAS) and three men were found suffering from stab injuries.
“A 20-year-old man was pronounced dead at the scene at 20:30 hours.
“His next of kin have been informed. Formal identification awaits.
“A post-mortem examination will be held in due course.
“The remaining males were taken by the LAS to a west London hospital.
“Their injuries are not being treated as life-threatening or life-changing.”
An LAS spokeswoman said it received a call at 7.38pm to an incident near the station.
She said: “We sent two ambulance crews, a first responder in a car and an incident response officer to the scene. A team from London’s Air Ambulance was also dispatched to the scene by car.
“We treated three patients at the scene. We have taken two patients to hospital as a priority. Sadly one patient died at the scene.”
Parsons Green Lane and the station have been closed by police and cordons are in place.