A fifth man has been arrested on suspicion of murder after a teenager was stabbed to death in Sydenham.
The 17-year-old was taken into custody yesterday. A 13-year-old and a 15-year-old, who were also arrested, have been bailed until later this month pending further investigation.
Two other teenagers arrested have been released with no further action.
Police and paramedics were called to Wells Park Road on Saturday at about 8.30pm following reports of a fight between two gangs.
An 18-year-old man was found with a stab wound. He died at the scene at 9.25pm.
A post-mortem examination at Greenwich Mortuary the following day found the cause of death as a single stab wound to the chest.
Formal identification is set to take place today and the next of kin have been informed.
A 17-year-old man was also stabbed and taken to a south London hospital. He has been described as being in a non-life threatening condition.
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 led up to this murder.”
Call 020 8721 4868 or 0800 555 111 anonymously with information.