Seven people, including four children, were found dead from gunshot wounds early Friday at a property in southwest Australia, near the popular tourist town of Margaret River, police said.
It appears to be the country's deadliest mass shooting in 22 years.
Police were called before dawn to a residence in the village of Osmington, some 13 miles northeast of Margaret River and 170 miles south of Perth. There, officers discovered the bodies of three adults and four children, according to the Western Australia Police Force.
Two of the adults were found outside, while the other victims were inside a building on the rural property. Two firearms were recovered from the scene, police said.
"Police are currently responding to what I can only describe as a horrific incident," Western Australia Police Commissioner Chris Dawson said at a press conference Friday afternoon. "It’s still very early in this investigation, but based on what we do know, this is clearly a tragedy."
Police were attempting to get in touch with the victims' relatives, Dawson said. He declined to release their names and ages.
Homicide and forensic crime-scene detectives traveled from Perth to assist in the investigation. Police have no information to raise concerns about wider public safety issues, Dawson said.
"This devastating tragedy will no doubt have a lasting impact on the families concerned, the whole community and, in particular, the local communities in our southwest," the police commissioner told reporters.
Since 1996, Australia's worst shooting incident before Friday's occurred in 2014, when a man killed his wife and three children before turning the gun on himself at the family's farmstead near the town of Lockhart in New South Wales state.
In contrast, the United States has been shaken by a surge in mass shootings in recent years as the nation remains sharply polarized in political debates over gun laws.
The United States has more guns per capita than any other nation in the world, with about four in 10 Americans saying they either own a firearm or live in a household with guns, according to a 2017 study conducted by the Pew Research Center.
The United States also has had the highest number of public mass shootings, defined as those that occur in relatively public places, according to a 2015 study conducted by University of Alabama criminology professor Adam Lankford.
The Associated Press contributed to this report.