A woman and three men have been arrested after a man was stabbed to death in north-east London.
The victim, who is thought to be in his 30s, was found with knife wounds in Matthias Road, Stoke Newington, on Wednesday evening.
He was given CPR by police prior to ambulance crews arriving but died at the scene.
A 33-year-old woman and three men, 57, 62 and 58, have been held on suspicion of murder and remain in custody.
Officers at Scotland Yard believe the victim was attacked on nearby Cowper Road and crime scenes remain in place at both locations.
Det Ch Insp Paul Considine said: "This attack took place in the early evening, in a residential street and in broad daylight.
"There would have been people around and I need those people to call police.
"Whatever you saw, whether the fatal assault, the events leading up to it or the aftermath, it is vitally important that you call us.
"It is only by people working with police that we can make London safe and your call may be vital in helping us understand how a young man came to be brutally killed."