A woman from Australian is now in critical condition in the hospital after her dog bit off her arm in North Queensland.

Emergency services were called to a house in the coastal city of Townsville around 07:00 local time (22:00 BST) on Friday, where a 34-year-old woman had sustained "life-threatening" injuries, according to BBC.

Her right arm had been severed below the elbow, but the detached part was retrieved by paramedics before she was rushed to a local hospital. She is in a serious but stable condition.

Police say they had "no other option" but to shoot the dog dead at the scene.

In a press conference, Senior Sgt Scott Warrick said police had arrived to find the woman bleeding heavily outside the house and the dog, believed to be a pit bull, inside.

"It was very angry, very aggressive... [it] was still trying to get outside."

Some officers barricaded the house while others applied a makeshift tourniquet to the woman's arm and gave first aid until paramedics arrived.

"I've been a police officer for 37 years... this is the first time I've gone to such a serious injury as a result of a dog attack.

"The injuries to this lady are just absolutely awful and we wish her a speedy recovery," Sgt Warrick told reporters.

He added that the dog was euthanised on the advice of animal control officers.

"I have dogs, and to see an outcome like this is absolutely heartbreaking, and we do understand people will be upset... but we were left with no other choice."

A second smaller dog was found uninjured at the scene and is being cared for by the RSPCA.

Two neighbours told the Australian Broadcasting Corporation the dog involved in the incident was known for being aggressive - with one showing them scars where he said it had previously attacked him.

Sgt Warrick said police may have been contacted about the dog before, but added that his team, the RSPCA and local council are all still looking into the specifics.

It comes a day after another attack in a Melbourne backyard, where a woman was critically injured and the three dogs responsible shot dead by police.

Local media have reported that two of the dogs were bulldogs and the third was a pit bull.