A fifth teenager has been arrested on suspicion of murder after an 18-year-old was stabbed to death in Sydenham.
The victim, named locally as James Hunter or Yardz, was found with a stab wound to the chest and pronounced dead in Wells Park Road on Saturday (May 31) night.
Police were called to the scene at around 8.30pm to reports of a fight between a group of youths.
A 17-year-old boy, who is currently in custody, is the fifth teenager arrested in the murder investigation.
A 15-year-old boy and a 17-year-old boy previously arrested have been released with no further action.
Meanwhile a 13-year-old boy and 15-year-old boy have been bailed pending further investigation and are due back later this month.
Detective Chief Inspector Russell Taylor of the Homicide and Serious Crime Command is leading the investigation.
He said: "A number of youths gathered in Wells Park Road before a fight broke out.
"Many people would have witnessed the attack as well as the aftermath.
"I would urge those people to contact officers so that we can piece together the events that lead up to this murder.”
An incident room has been opened. Call 0208 721 4868.
To remain anonymous, call Crimestoppers on 0800 555 111.