Six Dead in Shooting at Remote Australian Property

Police said they had been searching for a missing person in Wieambilla - 270km west of Brisbane, Queensland - when they were fired upon.

After a lengthy siege, three suspects were fatally shot by police. The motive remains unclear, authorities said.

Australian Prime Minister Anthony Albanese called it a "heartbreaking day" for Australia.

Four police officers - who are armed in Australia - initially went to the property on Monday afternoon local time, after a request from New South Wales police.

Constables Matthew Arnold, 26, and Rachel McCrow, 29, were shot dead as they approached the property. Another officer suffered a "bullet graze" and the fourth escaped without physical injury, police said.

A neighbor, 58-year-old Alan Dare, was killed by the suspects after going to the property to investigate.

The siege involved "many weapons" and continued for hours, before the suspects - two men and a woman - were shot by specially trained officers, authorities said.

One was identified as Nathaniel Train, 46, a former school principal and the missing person police had been sent to check on.

The others were his brother Gareth Train, 47, and Gareth's wife Stacey Train, 45, who co-owned the property.

Queensland Police Commissioner Katarina Carroll described the attack as an "unimaginable tragedy" and the force's largest loss of life in a single incident in many years.

The deaths will be investigated by the coroner and the police response will be examined by the force's ethical standards command, in line with standard practice.