A 20-year-old man was found stabbed to death at a petrol station in Harrow Weald last night.
The young man suffered fatal knife wounds to the body at High Weald Service Station in High Road, at 7.30pm. He was pronounced dead at the scene.
Another 20-year-old man also suffered stab wounds to his torso and was said to be in a stable condition at a west London hospital, said a Scotland Yard spokesman.
Officers from the Metropolitan Police's Homicide and Serious Crime Command team said they were yet to formally identify the victim. No arrests were made at the scene.
Police say they are looking for a second set of people in connection with the crime and that a post-mortem examination on the body of the victim will take place in due course.
Neighbours reported seeing a double-decker bus parked up on the southbound carriageway opposite the filling station, a franchise of Total UK, at around the time of the incident and witnessed a group of people milling around the casualty on the petrol station forecourt.
Residents also told people they heard raised voices, possibly Somali, and swearing shortly before the attack.
High Road is currently sealed off between its junction with Whitefriars Avenue and the entrance to Salvatorian College while Spencer Road, Wealdstone, is also closed, and traffic is being diverted.
Total UK did not wish to comment on the incident but said it is not believe the victims were staff members.