The incident happened at Crossharbour DLR station
The 21-year-old was detained yesterday, after the attack at Crossharbour DLR station on Friday evening.
Two men were stabbed during the incident. A 19-year-old died at the scene, while a second man was taken to hospital for treatment.
Detective Chief Inspector Paul Langley, from British Transport Police, 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. They are continuing to be supported by specially trained family liaison officers.
“I know the local community and many people across the country have been truly shocked by this senseless killing, and we will continue to work tirelessly to make sure those responsible face justice.”
Tags: Tower Hamlets, DLR, Isle of Dogs, Crossharbour