Six people, including two police officers, have been shot dead at a remote property in Australia's Queensland state, according to the police.

The violence began Monday afternoon when four officers arrived at a remote property in Queensland state. They arrived to investigate reports of a missing person and were ambushed. 

Two officers were fatally shot by two armed offenders, and a member of the public was also shot and killed.

After about six hours, two men and a woman were killed in confrontation with police, bringing the violence to an end, police said.

Prime Minister Anthony Albanese said it was a "heartbreaking day" for the families and friends of the officers killed.

"My condolences to all who are grieving tonight – Australia mourns with you,"  Albanese tweeted.