LONDON (AP) — A British police officer was shot dead inside a London police station early Friday while detaining a suspect.

London’s Metropolitan Police force said the officer was shot at the Croydon Custody Center in the south of the city. The 23-year-old man being detained also sustained a gunshot wound and is in critical condition in a hospital.

The force said no police weapons were fired.

It is rare for police officers to be shot and killed in the U.K., which has strict firearms laws.

“When a colleague dies in the line of duty the shockwaves and sadness reverberates throughout the Met and our communities,” said Metropolitan Police Commissioner Cressida Dick. “Policing is a family, within London and nationally, and we will all deeply mourn our colleague.”

The force has launched a murder inquiry and the independent police watchdog is also investigating.