A British police officer was shot dead inside a London police station early Friday by a suspect he was detaining, who then turned the gun on himself.

London’s Metropolitan Police force said the officer was shot at the Croydon Custody Center in the south of the city just after 2 a.m. He was taken to a local hospital where he was pronounced dead.

The 23-year-old man being detained is in critical condition in a hospital with a self-inflicted gunshot wound.

A view of Croydon Custody Centre where a police officer was shot in the early hours of Friday, Sept. 25, 2020, in Croydon, England.  A British police officer has been shot dead inside a London police station 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 early Friday.  (Aaron ChownPA via AP)

A view of Croydon Custody Centre where a police officer was shot in the early hours of Friday, Sept. 25, 2020, in Croydon, England. A British police officer has been shot dead inside a London police station 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 early Friday. (Aaron ChownPA via AP)

The force said no police weapons were fired.

Prime Minister Boris Johnson and other senior politicians expressed shock at Friday's death.

“We owe a huge debt to those who risk their own lives to keep us safe," Johnson said.

London Mayor Sadiq Khan said, “My heart goes out to the family of this brave officer, who has paid the ultimate price for helping to keep Londoners safe.”

“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.

It is rare for police officers to be shot and killed in the U.K., which has strict firearms laws. The officer, whose name has not been released, is the 17th from the London force to be killed by a firearm since 1945.

The last London police officer killed in the line of duty was Constable Keith Palmer, who was stabbed to death in March 2017 during a vehicle and knife attack outside Parliament.