Detective Acting Inspector Adam Henry, from the arson and explosives squad, said the mother and three children moved into the house last week.
He said arson chemists were still working on the cause of the blaze, and believed it started inside the rear of the house, while the children were found at the front of the home.
“This is an incredibly tragic incident and one that certainly would have been very confronting for the first responders, in particular the firefighters who did an incredible job to locate the children and get them out of the home swiftly,” Henry said.
He said police had spoken briefly to the children’s mother, who was with them at the hospital, and said investigators would formally speak to her again.
“She is understandably quite distressed by the incident and remains at hospital with her children,” he said.
“At this stage it’s too early to say …