A Certis Cisco auxiliary police officer, stationed at Changi Airport, accidentally fired a gun yesterday morning.

The incident occurred at 5.45am in a restricted staff-only rest area situated outside the airport's perimeter fence.

No injuries were reported following the "accidental discharge of firearm", a Certis Cisco spokesman said in a statement after The Straits Times reported the incident.

The police said they were alerted to the case at 6.09am.

This is not the first such incident involving an auxiliary police officer.

In February, a former Certis Cisco corporal who fired his revolver while playing a Russian roulette- style game, and then tried to cover up his actions by claiming that he lost two bullets in the toilet, was jailed for five months.

He committed the offence in August 2015 while on duty at an observation post at Tuas Checkpoint.

Despite such incidents, both Certis Cisco and Aetos, which also provides auxiliary police services, stressed that their officers undergo rigorous training before being given firearms.

The Certis spokesman said psychiatric assessments are also conducted to ensure that officers are fit for firearms training.

She said: "They are aware of the serious consequences of any misuse. Officers found abusing or misusing firearms will face immediate dismissal from service."

Retired police superintendent Lee Swee Thin, now a managing consultant at Top Criminal Justice Consultancy, said that when a firearm is accidentally discharged, it is usually due to officers' actions, although there is always a "remote possibility" of a mechanism problem.

He does not believe, though, that the use of firearms should be further restricted.

"Those who handle firearms would have been told of the precautionary measures to take, and how to draw their weapons under different circumstances," he said.