Passengers endured an early morning shock on Monday when their bus was involved in a collision with a police van.
Three passengers on the U4 sustained minor injuries and two police officers were taken to hospital after the crash at 6.35am on Monday, at the junction of Vine Street and Hillingdon Road, Uxbridge, as the bus was heading towards Uxbridge Station.
The bus driver was treated for shock by paramedics at the scene, and the two police officers were taken to Hillingdon Hospital in Pield Heath Road, Hillingdon, where they were treated and released.
The police van went into a crash barrier after hitting the front of the bus on the driver's side, and both vehicles were badly damaged.
The incident is now being investigated.
The crash closed Hillingdon Road for four hours while the scene was cleared, requiring diversions to the surrounding routes.
Adrian Jones, managing director of the bus company First London and Berkshire, said: "The incident is under investigation by the police and ourselves, and we are not in a position to make any comment on the accident circumstances until that is concluded."