Up to five bodies, including those of a woman and children, have been found in a house in a suburb of Perth, according to police in Western Australia.
The discovery was made at a home in Bedford after a man alerted officers at a regional police station.
The man, aged in his 20s, is in custody. It is not yet known whether the victims are related.
Western Australia Police Assistant Commissioner Paul Steel described the scene as tragic.
Police carry out an investigation at the property in Bedford, Perth (EPA)
He told a news conference: This is early and we’ve not yet fully examined the scene. We understand that there are adults and children involved.
Mr Steel said up to five bodies were found at the scene in Coode Street when police arrived and that an investigation was being carried out were.
I can say there was at least one woman but I can’t say more than that I’m afraid. The scene has not yet been forensically examined so the exact number of adults and children is actually unknown to me, Steel said.
He did not say how the people were killed or if any weapons were found.
This was the second major incident in Western Australia this year.