The children died with their mother and grandparents.
JACQUELINE LYNCH: I spent much of my day talking to neighbours yesterday and as I said, they were very friendly and very warming and they said, I guess, the words they used to describe this incident was shocked and they were horrified. Police were led to the property by a phone call before dawn, Dawson said.
Flowers have been left outside the Osmington property where the bodies of seven people were found.
Police said they went to the property after getting a telephone call.
Homicide detectives are now assisting police, he said, adding that there was no danger to the public. He declined to release the names or ages of the dead.
Police have revealed three guns found at the rural West Australian property belonged to the grandfather.
WA Police have made a number of services available to the officers dealing with the incident. That event was the catalyst for a significant strengthening of the country's gun laws. Known as the 1996 National Firearms Agreement (NFA), the law banned the possession, manufacture and sale of all semiautomatic firearms and pump-action shotguns other than in "exceptional circumstances", such as military and police use. It has a handful of farms, vineyards and stud farms.
"We are treating this as a matter in which six persons are subject of a homicide crime scene", he continued.
Speculation mounts that the deaths are being treated as a murder-suicide, but police have not confirmed that.
Dawson say police have no information to raise concerns about the wider public safety.
He emphasised that police did not believe anyone else was involved in the deaths and officers were not looking for any other suspects.
Two firearms were also located at the scene. All weapons must be registered, although many arrive illegally from overseas through organised syndicates.
A grandmother who was among seven people killed in a suspected murder-suicide in rural Western Australia has been remembered for her "deep commitment" to the environment.
"There was just a lot of love in that family". Dawson said the bodies had been there for several days before they were discovered.
Augusta-Margaret River Shire president Pamela Townsend said the incident had impacted everyone in the area.
"This is a strong, connected community and I know that we'll all support each other and we'll get through this together", she said.