Police have named a 16-year-old boy who was stabbed to death at a block of flats in south London.
Peter Hagan was discovered in the stairwell after police were called to Albon House in Neville Gill Close, Wandsworth, at 1.30am on Sunday morning.
"Although we await formal identification, we are satisfied the victim was Peter Hagan," police said.
The teenager was pronounced dead at the scene and a murder investigation is under way.
Nine people have been arrested in connection with the inquiry, eight of them have been released on bail.
The teenager is believed to have been attending a party in the tower block in the hours before his death, police said.
Detective Chief Inspector Nick Scola, from the Metropolitan Police’s homicide and serious crime command, said: "I need to trace everyone at that party, and in particular I am appealing for any information about a group of between five and eight males seen running from the scene into the surrounding streets and possibly through King George's Park."
:: Witnesses or anyone with information are asked to contact the incident room on 020 8721 4005 or call Crimestoppers , anonymously, on 0800 555 111.