Seven people have been found dead at a rural property in what is reported to be Australia’s worst mass shooting since 1996.
The bodies of four children and three adults were discovered in the town of Osmington in Western Australia (WA), 280km (170 miles) south of Perth.
Three generations of the same family were among the victims, Australia’s ABC News reported.
Police have not yet confirmed widespread reports of murder-suicide.
Officials did, however, say that two firearms were found at the scene and said there was no ongoing threat to public safety.
ABC News, quoting a family friend, reported that Katrina Miles and her four children were among the dead.
Her parents, Peter and Cynda Miles, were also killed, ABC said.
Police, however, have yet to formally identify any of the victims or to confirm the incident as a mass shooting.
“It appears that gunshot wounds are there, but I don’t want to go further than that,” said WA Police Commissioner Chris Dawson.
If confirmed, it would be Australia’s worst mass shooting since a massacre in Port Arthur, Tasmania, claimed the lives of 35 people in 1996.
The Port Arthur massacre led to comprehensive reform of the nation’s gun laws, drastically reducing the number of mass shootings.
Mr Dawson said the victims were believed to have lived at the property.
“The loss of any life is tragic, but four children and three adults – this is a significant tragedy,” he said.
Authorities were called to the scene at 05:15 local time (21:15 GMT on Thursday) after receiving a call from a “male person”, Mr Dawson said.
The commissioner did not give details of the call, but said it had been recorded.
He said specialist police officers from Perth would oversee a large-scale investigation.
There was no search for a suspect, he said.
Osmington is a tiny rural community about 20km from Margaret River, a popular tourist and wine-growing area.
One neighbour, Felicity Haynes, described the residents of the property as “lovely people”.
“They were a very socially-aware family – doing their best to create a safe community – and that is why it is so shocking to think that could be destroyed so quickly,” she told the Australian Broadcasting Corp.
Pamela Townshend, president of the Shire of Augusta-Margaret River, told Fairfax Media: “It’s sending shockwaves through the whole community – we’re all linked in one way or another, every family.”
After the 1996 massacre at Port Arthur in Tasmania, Australia enacted strict gun laws that banned automatic and semi-automatic weapons.
It has had one other mass shooting since Port Arthur – the murder-suicide of a family of five in New South Wales in 2014.