The incident took place in the Western Downs on Monday afternoon when four police officers were in attendance at a property on Wains Road at Wieambilla in relation to a missing person investigation.

As they were approaching the property, two police officers were shot by two armed offenders, and a member of the public was also shot and killed. Two other police officers were taken to a hospital with non-life-threatening injuries.

The alleged offenders, two men and a woman, were fatally shot during a confrontation with police shortly after 10.30 pm local time on Monday.

An emergency declaration was announced around the neighborhood and a crime scene has been established at the property.

The National broadcaster ABC news reported that local residents were told to stay indoors until further notice and multiple ambulances were called to the scene.

Police Commissioner Katarina Carroll said this is the largest loss of life the Queensland Police Service has suffered in one single incident in recent times and a sad reminder of the unpredictable nature of policing.

General president of the Queensland Police Union Ian Leavers described the killing as a ruthless and cold-blooded "execution," said ABC news.

"Police were responding to a call for a service for a missing person, it was simply that ... as soon as they entered the property, they were inundated with gunfire and they never had a chance," he said.

Australian Prime Minister Anthony Albanese expressed condolences to the victims.

"Terrible scenes in Wieambilla and a heartbreaking day for the families and friends of the Queensland Police officers who have lost their lives in the line of duty," he twitted.

"My condolences to all who are grieving tonight (Monday night) -- Australia mourns with you."

(With UNI inputs)