Three teenagers have been arrested after a 14-year-old boy was stabbed to death as he got off a bus in south London.
The Metropolitan Police said the victim died in hospital after suffering stab injuries in Burnt Ash Road, Lee, at about 9.45pm on Saturday night.
Three males, all believed to be in their mid-to-late teens, have been arrested on suspicion of murder and are in custody at a south London police station.
Initial reports suggest the victim was travelling on a route 202 bus through Lee Green towards Charlton.
Officers believe they know the identity of the victim, whose next-of-kin have been informed, and a post-mortem examination is scheduled to take place on Monday.
Both London Ambulance Service and the capital's air ambulance service attended the scene.
A Scotland Yard spokesman said: "As the victim alighted the bus in Burnt Ash Road he was attacked and stabbed.Officers are trying to establish if there was some sort of altercation on board the bus which led to the incident."
Detective Chief Inspector Mark Dunne, from the Met's homicide and serious crime command, said: "I am appealing for anyone who travelled on the route 202 bus on its way through the Lee area just before 9.45pm on Saturday night to speak to my officers.
"Did you witness an altercation or argument involving a group of male youths? I would also like to speak to anyone who was in Burnt Ash Road, where the victim got off the bus.
"I need to know what the series of events were which culminated in a 14-year-old boy losing his life."