Flags on government buildings will fly at half-mast in Queensland in memory of two early-career police constables killed in the line of duty.

The Story and Victoria bridges in Brisbane will be lit up in blue and white on Tuesday night in memory of the victims, 26-year-old Matthew Arnold and 29-year-old Rachel McCrow.

“I doubt that this will bring much comfort to the families and loved ones of those who were killed,” Queensland Premier Annastacia Palaszczuk said on Tuesday.

“They were so young…they were incredibly brave. These were absolutely callous, brutal acts.”

Police shot dead three people following a siege at a remote property 300 km west of Brisbane on Monday night, which came after the two officers and a neighbour were gunned down.

Constables Arnold and McCrow were sworn in to the Queensland Police Service in March 2020 and June 2021 respectively.

“Both under 30 years of age, both had wonderful careers and lives ahead of them,” QPS Commissioner Katarina Carroll said on Tuesday.

“Yesterday, as they did every day, they put their lives on the line to serve their community.

“In this awful incident, they made the ultimate sacrifice.”

ACT Policing sent their condolences after the tragic incident.

“We send our sincere condolences to our blue family in Queensland Police Service for the tragic loss of their two officers who were killed in the line of duty yesterday,” they said in a post on Facebook.

“We extend our sympathies to all families, friends and colleagues during this devastating time.

“May they rest in peace.”

Flags will also be flown at half-mast in Western Australia, the state’s police commissioner Col Blanch said.

“I know WA Police officers have also felt the impact of the deaths and many have reached out to their colleagues in Queensland to offer support,” he said.

The incident had left “a dark cloud” over Australia’s police community, Police Association of South Australia president Mark Carroll said.

“Never should a police officer, committed to his or her duty, colleagues and community, die in circumstances like these, ” he said.

The incident was a reminder of the “very real risks” police faced every day, Police Association of Tasmania President Colin Riley said.

“Policing in Australia is very networked and we have close colleagues in Queensland. Our condolences go to the police family in Queensland,” he said.

“Our thoughts are also with police who bravely contained and managed the subsequent operation to resolve this dangerous situation.”

The loss of lives had rocked the small communities around Wieambilla, Western Downs Mayor Paul McVeigh said.

“When lives are lost in small communities it impacts on everyone, especially when it’s our police force that we trust,” he told 4BC radio Brisbane on Tuesday.

“I’m sure there’s going to be a lot of grief and sadness as we move through this process.”