The mother of most of the eight children reportedly found stabbed to death in a house in the Australian city of Cairns has been arrested for murder, police said Saturday.

"The 37-year-old mother of several of the children involved in this incident has been arrested for murder overnight and is currently under police guard at the Cairns Base Hospital," detective inspector Bruno Asnicar told reporters.

The woman, who police said Friday was thought to be the mother of seven of the children and related to the eighth, has not been charged.

Queensland Police said she was assisting them with their enquiries.

"She's stable and being looked after," Asnicar said.

Cairns police said they were called to the house in the northern city and found the bodies of the children, aged between 18 months and 15 years.

Police forensic teams are still working in the house, but the bodies of the children have been removed. The mother sustained stab wounds herself and was removed from the house on Friday on a stretcher.

"She's stable and being looked after," Asnicar said.

Asnicar said it was too early to say how the children died, but reports have said they were stabbed to death.

"The bodies have been removed from that residence," Asnicar said.

"Autopsies will occur today. It will be after that we can comment about those sorts of things."

The murders have rocked Australia, still reeling from a dramatic siege in a central Sydney cafe this week, which began on Monday and left two hostages and a gunman dead, and prompted a huge outpouring of emotion.

The latest tragedy is reported to have been discovered by the mother's 20-year-old son who arrived at the home in the Cairns suburb of Manoora on Friday morning to find his siblings murdered.

"This is something that has caught everyone by surprise," Asnicar said. "Just an absolutely tragic event."