A pregnant woman and a man have been found dead at a home in the outback Queensland town of Charleville, in an apparent murder-suicide after a protracted overnight standoff with police.

Several streets in the remote town, 600km west of Toowoomba, were locked down by police on Wednesday evening after officers arrived at the property on King Street after reports of “a serious assault”.

An emergency declaration, under the state’s Public Safety Preservation Act, was in place for about eight hours.

When specialist officers entered the home, just before 1.45am, they found that a 45-year-old man and a 23-year-old woman were dead.

The incident will be investigated by Queensland police’s ethical standards command because it occurred during a police operation.

Police would not confirm whether the incident was being treated as a domestic violence situation.

Shaun Radnedge, the mayor of the Murweh shire council, said that based on the information he had been given “there is no ongoing risk to the public”.

“The situation has been brought to an end,” Radnedge said.

“This tragedy will be felt deeply across our small community. I know many people will be struggling to come to terms with what has happened.”