A teenager has been stabbed to death in an attack in east London.
The 18-year-old, who has not been named, was found with multiple stab wounds in Shernhall Street, Walthamstow, at 2330 GMT on Friday.
He died on the way to hospital. A 17-year-old youth has been arrested on suspicion of murder.
Police said an incident took place in Shernhall Street before the stabbing. A post-mortem examination is due to take place later.
Police are believed to know the name of the victim but are awaiting formal identification.
Det Insp Phil Rickells, of the Homicide and Serious Crime Command, said: "We would like to speak to anyone who may have seen an altercation take place on Shernhall Street prior to emergency services arriving."