A man has been arrested after a teenager was stabbed to death at a Docklands Light Railway station in London.
The 19-year-old died on Friday after the knife attack at Crossharbour DLR station in Poplar, east London.
A second man who was also found stabbed was being treated in hospital.
The British Transport Police said a 21-year-old man, of Tower Hamlets, east London, was being questioned on suspicion of murder.
Det Chief Insp Paul Langley said: "We have been working around the clock to trace those responsible for his death and this is a positive step in the ongoing investigation.
"I'd like to thank the victim's family for their patience and strength, and once again extend our deepest condolences to them."