Image copyright Elisa Rispoli/ Facebook Image caption The Rispolis

An American family camping in one of Canada's national parks has escaped an attack by a wild wolf.

Matt Rispoli was camping with his wife and two young boys in Banff National Park in Alberta when a wolf attacked them in the middle of the night.

Parks Canada says wolf attacks are very rare - wild wolves generally avoid humans altogether.

A stranger in a nearby tent helped Mr Rispoli fight off the wolf, and the family was able to flee.

Mr Rispoli's wife Elisa recounted the terrifying incident on Facebook.

"It was like something out of a horror movie. Matt literally threw his body in front of me and the boys, and fought the wolf as it ripped apart our tent and his arms and hands," she wrote.

From his own campsite next door, Russ Fee said he heard a woman scream. He ran outside with a lantern and saw the wolf trying to drag something out of the Rispolis' tent that turned out to be Mr Rispoli, by the leg.

In a split second, Mr Fee charged into action.

"It was just so quick and the screams were so intense, that I knew it was obviously a terrible situation, so I just kind of kept running at it and I just kicked it sort of in the back hip area," he told the CBC.

The wolf let go of Mr Rispoli's leg, but stood there. The two men continued to shout at the animal and threw rocks, until they were able to escape to Mr Fee's campsite. Mr Rispoli was treated for his injuries the next day in hospital.

The campsite was evacuated and Parks Canada tracked and captured the wolf. The agency said the Rispolis' campsite did not have any "significant wildlife attractants or food" that might have lured the wolf.

A subsequent veterinary exam determined the wolf was in "poor condition", the government agency said in a news release.

"The wolf's condition was likely a contributing factor for its unusual behaviour and this remains a very rare incident."