The group, wearing its own army green protective uniform, boarded a coach to North Point Police Station and were seen off by Commissioner of Correctional Services Danny Woo Ying-ming.

“They are under police’s command and will be deployed to guard key buildings,” a senior law enforcement source said. “They work 12 hours in a shift. Most of the gear they took is from the correctional services authority, as the prison elite members are well-trained to control riots.”

The officers were later seen walking around police headquarters in Wan Chai to get to know the area.

Earlier this week, the Post reported that about 80 riot control specialists from the department’s escort and support group would be on loan on a voluntary basis to the police force.

On Friday, a police spokesman said Commissioner of Police Stephen Lo Wai-chung had appointed no more than 100 prison officers as special constables that morning in accordance with section 40 of the Public Order Ordinance.

The source said these officers worked on a part-time basis to discharge the duties of special constables only when needed and requested, otherwise they continued their original work in the prisons.

“The special constables overcame a lot of burden, such as pressure from family, before they agreed to take the challenge, as police are seen as an attack target by protesters. They had been doxxed too,” the source said.

“The correctional authority will provide psychological consultation and anything that can help ease their burden.”

Peaceful Friday descends into violence as government issues staff warning

The elite prison officers will wear armbands stating that they are special constables when on duty. They are mainly sourced from its regional response team, which was established three years ago.

Before joining, members of the response team must receive more than 11 weeks of tactical and firearms training to prepare them for escorting high-risk inmates, and dealing with riots and other emergencies in Hong Kong’s prisons, the department said when the team was launched.

The team – the cream of the department – got its nickname from comparisons with police’s elite Special Duties Unit, or “Flying Tigers”.

Separately, Lo inspected a passing-out parade of probationary inspectors and recruit police constables as a reviewing officer at the Hong Kong Police College on Saturday morning – which could be his last appearance before he retires on Monday.

Police have been heavily criticised for allegedly using excessive force on protesters, and mistreating people in custody during the ongoing anti-government protests.

Lo said in the ceremony that although the force faced a great challenges over its public image, it would certainly win back the support and trust of Hong Kong citizens eventually. He also encouraged the passing-out officers to stand firm in their values and keep confident, to rise to the challenges arising from threats on public safety and order under the current social unrest.

“As long as the force stays united and remains steadfast, discharges its duties in an honest and above board manner, and continues to enforce the law impartially,” Lo said, adding that new surveys in 2018 showed the public had full confidence in the force.

“We must not forget our aspirations in joining the force, which is to complete the solemn mission of upholding the rule of law and fighting crime.”

Upon leaving the force after more than a third of a century of service, Lo said: “My heart is always with the force. It is my greatest honour to be able to lead this world-class professional police force.”