A teenager died after he was stabbed in a street.
Scotland Yard said the victim is thought to have been involved in an argument with a group of black youths prior to the stabbing in York Way, Islington, north London.
Police said two youths were arrested nearby and were taken to a north London police station where they remain.
Police were called to York Way shortly after 2am on Sunday.
The victim, who is white and is thought to be 18, was taken by ambulance to the Whittington hospital where he died, despite the efforts of hospital staff.
Scotland Yard said it is thought the victim was stabbed and his attackers then ran away.
"We are keeping an open mind regarding the motive," a spokesman said.
Police are searching for the murder weapon or weapons. The stabbing happened near York Way's junction with North Rd.
Police would like to speak to anyone who was in the area around the time of the stabbing or who was in Shillibeers pub nearby. They keen to find out where the victim was prior to the stabbing.
Anyone with information should call 0208 345 3715 or call Crimestoppers anonymously on 0800 555 111.
