Australian police said Saturday they had arrested the mother of all but one of eight children reportedly stabbed to death in the northern city of Cairns, as vigils were held to mourn the tragedy.
Officers have not revealed the cause of death of the children, the youngest of which was a toddler and the oldest a teenager, but said knives were found at the house where the bodies were discovered on Friday morning.
"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.
Flowers and teddy bears were laid near the crime scene and church services were held overnight in Cairns, where police said they are working closely with the Torres Strait Islander community to which the family belonged.
Police have confirmed the dead as four girls -- aged two, 11, 12 and 14 and four boys aged five, six, eight and nine, but said they would not name the family for cultural reasons. In some indigenous cultures it is considered disrespectful to say a deceased person's name.
The woman arrested is the mother of the seven younger children and the aunt of the 14-year-old girl. She has not been charged, but Queensland Police said she was assisting them with their inquiries.
"She's stable and being looked after," Asnicar said, adding that the woman, who has stab wounds to her upper body, was "awake... lucid and speaking". He could not say whether her wounds were self-inflicted.
The murders have rocked Australia, which is still reeling from a dramatic siege in a central Sydney cafe this week that left two hostages and a gunman dead and prompted a huge outpouring of emotion.
"This is just an ordinary neighbourhood," Asnicar said. "A lot of good people, a lot of kids in the area and this is just something that has caught everybody by surprise. It's absolutely tragic."
- 'Everyone is in shock' -
A makeshift memorial has been established in a park near the crime scene, with scores of people visiting on Saturday to leave flowers, candles and toys in remembrance of the children.
Torres Shire Council Mayor Pedro Stephen told Australian Associated Press that the entire region was grieving.
"It's like a bomb has gone off," he said. "Everyone is in shock."
"There will be people who have never, ever been to Cairns who will be touched by this tragedy," added Acting Assistant Police Commissioner Paul Taylor.
Queensland state minister Tim Nicholls, who laid a wreath at the site, said police had not yet explained the motive behind the killings.
"As a father myself with three children under 15, I can only imagine the grief this community is feeling as they come to grips with the events," he said.
The dead children were reportedly discovered by the mother's 20-year-old son when he arrived at the house in the Cairns suburb of Manoora on Friday morning.
Reports said a woman was heard screaming in the house on Thursday night, with Brisbane's Courier-Mail saying she had shouted: "Don't let them take away from us. God bless us. Forgive me for what I'll do."
A 13-year-old girl who walked a friend who lived in the house home on Thursday night said she had met the mother, who had given her money for a taxi ride home.
"She was saying stuff about God and other stuff," she told Australian Associated Press. "She said: 'Papa God gave me the power to do anything'."