Police have praised bystanders for helping save a 17-year-old girl attacked by a large, mixed-breed dog in the New South Wales Hunter Valley.

Emergency services were called to a home on Broughton Street about 11:30am on Thursday, to reports of an unprovoked attack.

They found the girl with critical injuries to her face, neck and back.

She had been visiting a friend when the attack occurred.

Bystanders who witnessed the attack pulled the 10-year-old dog off the girl before calling for help. 

Police said the dog was a mix of boxer, bull Arab and Irish wolfhound. 

Paramedics treated the teenager before she was flown to Newcastle’s John Hunter Hospital in a critical condition.

She remained in intensive care on Friday, with her condition unchanged.

an aerial image of a regional town

Singleton is a tight-knit rural community. Mayor Sue Moore says residents have been shocked by the attack. (ABC News)

Bystanders first on scene

Acting Hunter Valley Local Area Police Commander Justin Cornes today praised bystanders for coming to the girl’s aid.

“Passers-by were first on scene,” he said.

“Certainly running into a scene which they didn’t know the full circumstances and to jump in there and remove the dog, which was at the time obviously very aggressive.

“An incredible act given the circumstances.”A policeman and a paramedic standing side by side, outside a police station.

Justin Cornes and paramedic Josh Parfrey have praised bystanders for saving the girl. (ABC Newcastle: Keely Johnson)

NSW Ambulance intensive care paramedic Josh Parfrey said the actions of the bystanders were critical in what was a confronting incident.

“They provided basic first-aid … before the ambulance arrived, trying to stem some bleeding and keep the wounds covered,” he said. 

Mr Cornes said police used a firearm to euthanise the dog, with permission from the owner. 

“Police … used a service weapon to euthanise the dog to allow emergency services to continue that treatment,” he said.

“Speaking to the owners, [they said] that the dog’s actions on the day were out of character.”

Police were assisted at the scene by Singleton City Council rangers.

Mr Cornes said the dog was in a fenced yard and the attack did not occur on the street.

Six NSW Ambulance resources, intensive care paramedics and the Westpac Rescue helicopter, with a retrieval doctor and critical care paramedic, attended the scene. 

School offers support

The girl is a student at Singleton High School and was on study leave preparing for exams.

The New South Wales Department of Education has issued a statement on the school’s behalf.

“Our thoughts and best wishes are with the injured student, their family and those affected,” the statement read.

“We are providing support to students and staff at the school.”

Inquiries are continuing.