A 25-year-old man has died after being assaulted and stabbed in west London, Scotland Yard said.
The victim, who has not been named, was found injured in Old Oak Road, Shepherd's Bush, at around 3.55pm on Thursday, Scotland Yard said.
Police believe the man was attacked outside Ollgar House, a block of flats in Ollgar Close, before staggering to the nearby street.
Officers and London's Air Ambulance attended but he was pronounced dead at the scene at 5pm.
Two men aged 27 and 28 have been arrested on suspicion of murder and remain in police custody.
Next of kin have been informed and a post-mortem examination is due to be held.
Detective Inspector Beverley Kofi said: "This is another tragic murder with a young male victim who has met a violent death.
"We believe that the incident started at Ollgar House, in Ollgar Close, and the victim was assaulted and stabbed before staggering and collapsing in Old Oak Road.
"We believe there were a number of people involved, but we are still working to establish the circumstances and a possible motive.
"We have made two arrests and continue to pursue a number of lines of inquiry. We need the public's help to piece together what happened - who the victim was seen with, the incident itself and the immediate aftermath."
Anyone with information is urged to contact police on 0208 358 0100 or Crimestoppers anonymously on 0800 555 111.