A man has died following an early-hours stabbing at a house in south London.
Police officers found the victim at an address on Drakefield Road, Tooting, after being called at 3am on Saturday.
Believed to be in his early 20s, the man was given first aid but died shortly after arriving at hospital, the Metropolitan Police said.
He is yet to be identified.
A 29-year-old man - who also sustained stab injuries - was arrested on suspicion of murder and remains in custody after being discharged from hospital.
Police said a 17-year-old girl was also taken to hospital after being stabbed in the hands, but is not in a life-threatening condition.
All three people involved are thought to know each other.
A murder investigation has been launched and anyone with information is asked to contact police.