A teenage boy was stabbed to death and two others injured in an attack believed to have happened after an argument outside a flat.
Police were called to reports of a stabbing in Erith, Kent, at around 3am and found the three youths, all thought to be in their mid to late teens.
Scotland Yard said all had stab wounds and that one of the victims was pronounced dead at the scene, while the other two were taken to the Royal London Hospital.
A murder inquiry was launched after the stabbing at Verona House, Waterhead Close in Erith, but no arrests have yet been made.
One of the two injured youths is still in hospital in a serious and stable condition but the other has since been discharged.
The teenager who died has not yet been formally identified and police are in the process of tracing his next of kin.
A post mortem will take place in due course.
A Metropolitan Police spokesman said: "We are investigating the circumstances of the incident and retain an open mind re motive.
"We believe the incident happened following an altercation with a suspect or suspects who then left the flat. We have no further details or description(s) at this early stage."
Anyone with information about the attack should contact Crimestoppers on 0800 555 111.
