Four officers went to a rural property at Wieambilla on Monday on a missing person inquiry for former primary school principal Nathaniel Train, but were met with gunfire from three people.

Constables Matthew Arnold, 26, and Rachel McCrow, 29, were shot, with the Queensland Police Union saying they were then “executed” while on the ground.

“This ruthless, murderous trio, they have gone and executed the two police officers on the ground in cold blood”, union president Ian Leavers said.

“We have never seen anything like this. It is an absolute tragedy.”

“This was a pure execution. They had no chance.”

A third officer reportedly ran into scrub which the offenders then set alight, while a neighbour who responded to the gunfire was also shot dead. A fourth officer escaped with a gunshot wound.

The three attackers – Nathaniel Train, his brother Gareth and his wife Stacey – were shot by police reinforcements later on Monday night.

NSW police last week launched an appeal for public assistance to locate 46-year-old Nathaniel Train, last seen at his residence in Dubbo on December 16, 2021.

Today, Albanese addressed the nation from Kirribilli House via a televised address.

He said all Australians were saddened and shocked by the tragic loss of life.

“This is, indeed, a devastating day for everyone who loved these Australians,” he said.

“This is not a price that anyone who puts on the uniform should ever pay. We can never count the true cost.

“My heart goes out to the families and loved ones of all those affected by this tragedy. With honour, they served and Australia mourns with you today.”

Opposition Leader Peter Dutton, himself a Queensland police officer before entering politics, said it was a shocking incident.

“When you have a few police officers who are turning up to check an address, walking up the driveway and they’re gunned down in a cold-blooded style, that will send a shiver down the spine of any police officer attending any job today,” he said.

“Of course the police family is absolutely devastated.

“People will be scarred from the experience. It’s time for our community, for our country to come together around police and support them.”

Nationals leader David Littleproud, who grew up in the area where the incident occurred, said the community was numb in the wake of the shooting.

“Chinchilla and Tara are both quiet, peaceful country towns. The shocking event that unfolded yesterday is not what our community is,” he said.

“My thoughts are with the two brave police officers and the member of the public who lost their lives. The police community will be raw today and we grieve with them.”

-with AAP