A British police officer has been shot dead by a man who was being detained at a custody centre in south London in the early hours of Friday.
Police said the officer was killed while a man was being detained at the Croydon Custody Centre. A 23-year-old man was detained at the scene and he was taken to hospital with a gunshot wound and is in a critical condition in hospital.
Officers did not open fire and a murder investigation is underway, police added.
"This is a truly shocking incident in which one of our colleagues has lost his life in the most tragic circumstances," London police chief Cressida Dick said.
"We are in the early stages of the investigation and are still working to establish the circumstances surrounding the incident and we will provide further updates when we have them."