COPS on Perth streets will be armed with semi-automatic AR-15 rifles by early spring in a bid to combat terror or “active shooter” attacks.

In total, 120 officers from the recently expanded regional operations group are currently being trained to use AR-15s.

The weapons will be provided in the group’s vehicles contained within new secure locked boxes.

Police Commissioner Chris Dawson said the aim was to complete the rollout by the end of September.

“I’ve personally seen the training under way and I’ve seen the fitout that has occurred with our mobile vehicles,” he said.

“I’m very pleased with the progress they’re making, so having spoken to both the trainers and those officers in the regional operations group and our tactical response group who are working very closely together on this, our milestone for September ... is on target.”

Camera Icon An AR-15 Sporter SP1 Carbine. Credit: M62

Currently, only TRG officers and some police stations in regional WA are equipped with AR-15s.

The regional operations group is based at Neerabup, Warwick and Rockingham.

Mr Dawson recently told Parliament: “Although the Australian public terrorist threat alert is listed as probable, it is very important that aside from the normal policing that goes with our duty, we must also ensure that we have a full capability for any matters that might touch on active armed-shooter situations or indeed countering any terrorism.”

In evidence to a parliamentary inquiry late last month, the WA Police Union said its members had long wanted to be equipped with AR-15 rifles in the metropolitan area, with president George Tilbury saying there were concerns about how quickly the TRG could respond to incidents that needed immediate action.

It’s understood that the two versions of the Glock pistol, the standard weapon issued to officers, can fire either a 15 or 13-round magazine, with a bullet velocity of 300m a second and an effective range of 30m. AR-15s have a 200m range and 900m a second velocity.

Progress is also being made on issuing frontline police with stab-proof ballistic vests. After campaigning by the union, Police Minister Michelle Roberts last year committed to a rollout. A working group with police and the union had been set up to ensure the best possible equipment was provided, Mr Tilbury said.

He said in November 2016, there were 1035 pieces of tactical body armour Statewide for 5242 frontline cops. “In other words, less than a fifth of WA officers can be considered to have sufficient protection at this point in time,” Mr Tilbury said.