BRISBANE, Australia (AP) — Australian police are investigating the extremist views of three people who shot and killed two officers and a neighbor at a rural property before they were killed hours later by police in a gunfight.

In all, six people died in the violence Monday in Queensland state. The killers have been identified as former school principal Nathaniel Train, 47, his brother Gareth, 46, and sister-in-law Stacey, 45.

Queensland Police Commissioner Katarina Carroll said late Tuesday that investigators would look at the possible extremist links of the killers after a series of posts under the name of Gareth Train were found on conspiracy theory forums.

The posts include references to anti-vaccine sentiments and claims that other high-profile shootings were hoaxes or false-flag operations.

“It’s very difficult at the moment for us to reason with what has happened, there are no obvious reasons,” Carroll told the Australian Broadcasting Corp. But she added she had no doubt that over the coming days and weeks, police would come back with some insight into the tragic events that unfolded.

Carroll said every possible motive for the killings was being examined, including whether it was a premeditated attack on the officers.

“Some of the stuff that’s online from these people, we will investigate what they have been doing not only in recent weeks but in recent years, who they’ve been interacting with," she said.

Four officers arrived at the property in the town of Wieambilla, in Queensland state, to investigate reports of a missing person. They walked into a hail of gunfire, Carroll said, and it was a miracle that two officers managed to escape and raise the alarm.

Those killed were Constables Matthew Arnold, 26, and Rachel McCrow, 29, along with 58-year-old neighbor Alan Dare.

One of the officers that escaped, Constable Randall Kirk, 28, was recovering at a hospital Wednesday from shrapnel wounds. He said he and his wife wanted to thank everybody "from the Prime Minister down” for their messages of support.

“I’m feeling fine, just a little sore. My main thoughts are with the other police families at this awful time,” Kirk said in a statement released by the police union. “It means a lot to know the community cares for us all."

Prime Minister Anthony Albanese earlier told reporters in Sydney that the country mourned with those affected.

“This is, indeed, a devastating day for everyone who loved these Australians, and our hearts go out to those in the grip of terrible grief,” he said. “We know that this news has fallen hard on a close-knit and caring Queensland community. As well as, of course, the community to which all police officers belong.”

He said officers across the nation know the risks they face, yet do their duty.

“And today and every day I pay tribute to each and every one of the police officers who serve their local communities and who serve their nation,” Albanese said. “This is not a price that anyone who puts on the uniform should ever pay.”