Some members of London’s police force are refusing to carry firearms after a colleague was charged with murder in the fatal shooting of an unarmed Black man.

Such a charge against a police officer is extremely rare in England.

The Telegraph newspaper reports that more than 300 officers, about 10% of the armed police, have refused to carry their weapons following their colleague’s charge.

The officers’ move has prompted Scotland Yard to ask the Ministry of Defense for help with counter-terrorism policing. The MoD would provide London with soldiers who would do specific tasks, but not routine police work.

Only about one in ten police officers in London carries a weapon, after undergoing intensive training.

Chris Kaba, 23, was the unarmed Black man who was killed in an encounter with police last year.  The Associated Press reports Kaba was shot by single bullet as he sat in his car.

The officer accused of killing Kaba has not been publicly named. His trial is expected to begin next year.