A teenage cyclist suffered serious head injuries during a crash involving a police car responding to a 999 call.
The 13-year-old was involved in the accident at the junction of Talbot Avenue and Oban Road, in the Winton area of Bournemouth, on Tuesday night.
The boy, from Bournemouth, is receiving specialist treatment at Southampton General Hospital. He is said to be in a critical but stable condition.
The Independent Police Complaints Commission has been informed.
The teenager was initially taken to Poole Hospital, but later transferred to Southampton, where his parents are at his bedside.
The two police officers in the car were not hurt.