Australian teenager charged with murder after 10-year-old sister stabbed to death

A 17-year-old girl has been charged with murder after her younger sister was found stabbed to death in the latest knife attack in Australia's New South Wales (NSW).

Emergency services responded to reports of a stabbing at about 3.45pm Monday at a home in Boolaroo, about 20km west of Newcastle.

Paramedics treated the victim, 10, for stab wounds to her upper body but she died at the scene, NSW police said in a statement.

The victim's older sister was arrested at the scene and interviewed before being charged with domestic violence-related murder.

The teenager has been refused bail and is scheduled to appear at a children’s court on Tuesday.

Deputy superintendent Daniel Doherty said the two sisters were the only children in the house when the attack took place.

“My thoughts go out to the mother at home having lost a 10-year-old tragically and now … her other daughter is facing court allegedly responsible for killing the 10-year-old,” Mr Doherty told reporters.

“It’s a tragic circumstance. It’s hard to imagine, it is unthinkable that this could happen to a 10-year-old."

Mr Doherty said the attack appeared to have occurred "completely out of the blue", ruling out any connection to the recent fatal knife attacks in NSW.

Neighbour Cindy Holloway said the two daughters had lived in the home with their mother and grandmother for three years. Their house was on a "very quiet" street with many renters and older residents, she added.

MP Greg Piper said the stabbing had impacted two school communities and devastated everyone in the Lake Macquarie area. "The family and the community will live with the implications of this for many years to come,” he said. "Wherever I and my office can provide support, we will."

This was the third reported fatal stabbing incident in NSW in four days. On Friday, a 16-year-old boy was allegedly stabbed in the neck in Narromine and a 28-year-old was stabbed while in Quakers Hill.

“The wider issues around knives in the community have been looked at by the government, and obviously NSW police will be at the table to provide advice when necessary,” Mr Doherty said.