Eight children have been found stabbed to death at a house in Cairns, Australia. The children are reportedly aged between 18 months and 15 years.

Police were called to a property in the suburb of Manoora following reports of a woman with serious injuries. During the search of the house the bodies of the children were discovered.

The 34-year-old woman, reportedly the children's mother, has received treatment for her wounds. She is said to be in a stable condition at a hospital where she is being questioned by police.

Queensland Police Detective Inspector Bruno Asnicar said: "As it stands at the moment, there's no need for the public to be concerned about this other than the fact that it's a tragic, tragic event.

"The situation is well controlled." He said detectives had not yet determined the relationship between all of the children and the woman.

But Lisa Thaiday, who said she was the woman's cousin, said the children were all siblings and that the woman was their mother.

Ms Thaiday said another sibling, a 20-year-old man, came home and found his brothers and sisters dead inside the house.

She said. "We're a big family...I just can't believe it."

Cairns Post reporter Scott Forbes, at the scene, said: "I've spoken to some of the family members and they say the woman, who is the biological mother, actually has more children but the other kids weren't at home at the time. So of the children she does have, eight of them are now dead."

"Many of the people here are actually connected to the family or relatives of the family. They are very shocked. They said they were a happy family and were enthusiastic about Christmas."

"They've said she was a very proud mother who was very protective of her children, so everyone lining the streets here is reeling right now."

The street is in lock down and a crime scene will remain in place for at least another day, police said.

Neighbour Bessie Mareko says what has happened is tragic.

Cairns MP Michael Trout said the close-knit community was in shock over the "dreadful tragedy".

"How can anyone harm innocent children is on everyone's lips at this moment," he said.

Australian Prime Minister Tony Abbott called the events in Cairns "heartbreaking" and acknowledged that these were "trying days" for Australia.

The deaths come as Australia is still feeling the shock of the deadly siege in a Sydney cafe earlier this week.

Amy Stewart from 4CA News spoke to Newstalk Breakfast this morning and told the show that the woman in question is speaking to police.