Detectives have launched a murder inquiry after a street cleaner was stabbed when he tried to stop a burglar from escaping in West London.
The 40-year-old victim, who was from Eastern Europe, died in St Mary's Hospital, Paddington.
He was attacked and stabbed in the torso in Rylet Road, West London, after apparently trying to stop a man fleeing the scene of a burglary.
A Scotland Yard spokesman said six people were arrested in connection with the incident.
One, a 30-year-old man, is being held on suspicion of murder at a central London police station.
Two other men and three women were detained on suspicion of assisting an offender.
Police believe they know the identity of the victim but are still awaiting formal identification.
Officers are appealing for witnesses to the incident, which happened shortly before 2pm on Wednesday afternoon.