A teenager has been stabbed to death at a house party in south-west London.
The boy, believed to be 16, was found stabbed in a ground floor stairwell at Albon House, in Neville Gill Close, Wandsworth.
London Ambulance Service was called at 01:30 GMT on Sunday. He was confirmed dead at the scene and next of kin have been informed.
A number of people have been arrested and are in custody at various central and south London police stations.
The Met did not confirm the exact number of people who have been arrested.
A post-mortem examination will be scheduled in due course.
Det Ch Insp Nick Scola, of the Homicide and Serious Crime Command, said: "I need to trace everyone at that party.
"In particular I am appealing for any information about a group of between five and eight males seen running from the scene into the surrounding streets and possibly through King George's Park."