UPDATED 5.40pm: Police in Queensland have now arrested the woman found with stab wounds at a house in Cairns, where 8 children died.

She is believed to be the mother of 7 of the children, according to AAP. 

The 37-year-old is under arrest in hospital, and police say she's been co-operating with their investigation.

But Detective Inspector Bruce Asnicar says the woman is yet to be formally charged.

"We're not looking for anybody else, we're comfortable that the community at large is safe and have no need for concern," he says.

Asnicar says several knives have been found, and the house is now the subject of a detailed study by a forensics team.

"They're looking for the order of the actions that occurred," he says.

"They're looking for any trace evidence that's in the residence itself, and they're looking for blood spatter patterns."

Detective Inspector Asnicar says police have been talking with the suspect who remains under guard in hospital.

"At this stage we're not looking for anybody else. We're comfortable that the community at large is safe and there's no need for concern."