LONDON (AP) — The head of London’s police force is calling for increased legal protections for officers who use force in the line of duty after more than 100 officers refused to carry guns to protest murder charges filed against one of their colleagues.

The revolt by specially trained firearms officers has raised concerns about the Metropolitan Police Service’s ability to respond to some incidents, and the military has agreed to provide backup for counterterrorism operations. Fewer than 10% of London police officers carry guns.

Police Commissioner Mark Rowley wrote to Home Secretary Suella Braverman late Sunday welcoming her decision to review the rules governing armed police and calling on her to “let the police police.” Braverman, whose department oversees policing, announced the review earlier in the day.

“We rely on officers who are willing to put themselves at risk on a daily basis to protect the public from dangerous criminals including terrorists,’’ Rowley said. “Officers need sufficient legal protection to enable them to do their job and keep the public safe, and the confidence that it will be applied consistently and without fear or favour.”

An unidentified officer appeared in court on Thursday after he was charged with murder in the shooting of an unarmed Black man in south London on Sept. 5, 2022. Chris Kaba, 24, died after he was struck by a single gunshot fired into the car he was driving.

Rowley stressed that such incidents are very rare. London police respond to about 4,000 armed incidents every year, with officers firing their weapons less than twice a year on average, Rowley said in his letter to Braverman. That means that 0.05% of armed operations result in shots fired by police, he said.

The Metropolitan Police Service, with more than 34,000 officers serving about 9 million people, is Britain’s largest police department. About 2,500 specially trained officers are licensed to carry guns.

The tensions over armed officers comes as Rowley tries to rebuild public confidence in his force following a series of scandals, including a serving officer who was convicted of kidnapping and murdering a young woman in 2021.

Rowley has made it a priority to root out bad officers and improve training after an independent review found widespread racism, misogyny and homophobia in the department.

Rowley said police should be held to the “highest standards,” but the current system leaves good officers facing lengthy investigations and legal proceedings even when they follow their training.

“There is a concern on the part of firearms officers that even if they stick to the tactics and training they have been given, they will face years of protracted legal proceedings which impact on their personal wellbeing and that of their family,” Rowley said.