Scotland Yard detectives are investigating the fatal stabbing of a 17-year-old boy.
Metropolitan Police said the teenage victim died in hospital shortly after 6pm today.
Emergency services were called to Caldy Walk in Islington, north London, following reports the boy - who has not yet been identified - had been stabbed.
The death will be investigated by detectives from the Homicide and Major Crime Command.
A police spokesman confirmed the Met were looking for a suspect or suspects.
In a statement, the force said: "At this early stage, officers retain an open mind as to any motive. There has been no arrest."