Seven people, including four children, were found dead in a house in Western Australia.
Police speak of "an incredible tragedy" and the evidence so far shows that the perpetrator, after killing the six victims, shooting them, then committed suicide.
The bodies were found at a home in the village of Osington on Friday morning. This is the deadliest shooting attack in the country since 1996, when 35 people were killed in Port Arthur.
The bodies of two adults were found outside the home, while five more bodies were found inside the house, according to police.
"Police are investigating what can only be described as a horrific incident," the police chief told reporters. "This incredible tragedy will undoubtedly affect the families (of the victims) and the whole community."