Update 7.26pm: Police are seeking a second man in relation to a car crash that killed three teenage pedestrians in west London on Friday night.
A 28-year-old man has been arrested on suspicion of dangerous driving after a black Audi, believed to be travelling at speed, mounted the pavement on Shepiston Lane, Hayes.
It is understood the three victims, named locally only as George, Harry and Josh, had been on their way to a birthday party at a nearby football club with friends when they were killed.
The suspect was being questioned at a north London police station on Saturday night.
Now the Met have said they believe at least one other male travelling in the Audi fled the scene.
The second male has yet to be apprehended and investigators have not ruled out more passengers being in the car.
The Met said in a statement: "Enquiries are ongoing to establish the full circumstances of the collision and the number of occupants in the vehicle involved."
Earlier: Three teenagers dead after collision at UK bus stop
Three teenage boys have died after a car ploughed into a bus stop.
Police were called to Shepiston Lane in Hayes at 8.41pm on Friday night following reports of a road traffic collision.
Despite the efforts of paramedics, all three boys were pronounced dead at the scene.
The victims have yet to be formally identified, but are believed to be approximately 16 years old.
A 28-year-old man who was inside the vehicle - a black Audi - has been arrested and was taken to a west London hospital for treatment.
Police have said that the incident is not being treated as terror related, and have urged anyone who may have witnessed the crash to come forward.
Other teenagers standing with the group at the bus stop, which is close to the Esso petrol station, were unharmed in the crash.
All of the next of kin of the deceased have been informed, the Met Police said.
Investigators have said they are still trying to establish the sequence of events that led up to the collision, and whether there were any other occupants in the vehicle.
The road was closed while the incident was investigated, but the closure has since been lifted.
Officers from the Met’s Road and Transport Policing command have urged anyone who may have witnessed the crash to come forward.
Detective Jane Shaw, of the Serious Collision Investigation Unit, said: "These are horrific circumstances that have resulted in three young people losing their lives; I need anyone who saw what happened to contact police immediately.
"Did you see this Audi before the collision, or in the moments leading it up to it? I would urge you to speak to us to assist us with our investigation."