A man was battered to death in a clash between rival gangs in Lewisham at the weekend.
Police were called to reports of a disturbance involving Tamil groups in Lewisham High Street at 9.20pm on Saturday.
A man, believed to be aged 22, was found collapsed at the scene and taken to hospital where he died yesterday.
Police say they know his identity but they are awaiting formal identification.
A post mortem found the case of death was severe blunt trauma to the head.
Detective Chief Inspector Graeme Gwyn, who is leading the murder inquiry, said: "I would appeal to anyone who was in the Lewisham High Street area around the time of the incident to contact my team.
“At this early stage we believe the victim was attacked by a group of males outside Lewisham Library. If you witnessed this assault, or the events leading up to or immediately after the assault, please call the incident room."
Three men were arrested and bailed pending further inquiries.
Anyone with information should call 0208 721 4805 or call Crimestoppers anonymously on 0800 555 111.
