A visitor to Yellowstone National Park in the US state of Wyoming has become the second person in just three days to be attacked by a wild bison.
The 71-year-old women inadvertently approached the animal as she returned to her car, causing it to charge.
Officials said she was taken to hospital, where she was treated for non-life threatening injuries.
The attack comes after footage emerged on Tuesday showing another bison at the park charging at and goring a visitor.
The incident occurred as the 34-year-old man from the state of Pennsylvania and his family were walking along a boardwalk near the park's iconic Old Faithful geyser.
Video footage obtained by US networks showed the man hurriedly moving his child out of the bull bison's path before he was thrown in the air.
BISON ATTACK: Officials in Yellowstone National Park are investigating a terrifying incident when a man and his son were tossed by a wild bison. Officials say they got too close to the male animal and it charged at them. pic.twitter.com/jeffFgxZTf— CBS Evening News (@CBSEveningNews) June 29, 2022
Park officials said he was later treated at a nearby hospital in Idaho for an arm injury.
A 25-year-old Ohio women was also attacked by a bison at the end of May in the first reported attack of the year.
She was tossed 10ft (3m) in the air after coming too close to the animal during a hike in the park, officials said.
Bison are extremely aggressive and territorial animals. Yellowstone officials have repeatedly warned that the bull bison living at the park are wild and can be dangerous when approached.
Park officials say bisons, which can travel at speeds of up to 30mph (48kmh), have injured more people in Yellowstone than any other animal.
In advice issued to visitors, park rangers suggest staying at least 75ft (23m) away from wild bison at all times and, if coming into contact with the animal is unavoidable, to "turn around and go the other way to avoid interacting with a wild animal in proximity".
Yellowstone is home to the largest collection of bison on public land in the US, with about 5,000 of the animals in two major groups.
Bison are the largest land-dwelling mammals in North America, and can weigh up to 2,000lb (900kg).