A 21-year-old woman who was planting trees was seriously injured by a bear in western Canada in what authorities have called a "defensive attack."

The attack happened shortly after 3 p.m. on Thursday near Bearhole Lake Provincial Park outside of Tumbler Ridge, a small town in northeastern British Columbia, according to a Friday news release from the province's Conservation Officer Service.

"The bear first bluff-charged and the victim retreated to a nearby roadway, where the bear attacked," officials said.

The bear eventually ran off and a coworker of the woman came to her aid and called for help, the agency said.

The victim was transported via helicopter to a hospital in Prince George and authorities said she is now in stable condition.

Conservation officers who responded to the scene determined there had been bears in the area, but they did not spot any. Officials say they don't have conclusive evidence but they believe it was a grizzly bear that attacked the woman.

According to statistics released by the British Columbia Ministry of Environment, Lands and Parks, there are an estimated 120,000-160,000 black bears in the province -- about one bear for every seven square kilometers. The province's grizzly bear population, estimated at 10,000 -13,000, is classified as vulnerable.

Bear-human conflicts are considered "relatively rare," the ministry said, unless the animals are startled or protecting their cubs or food.

However, last October, a "rare predatory attack" by a black bear left three people injured, two seriously, the CBC reported. That attack also occurred in northeastern British Columbia, outside the city of Dawson Creek.

Since 2019, calls about predatory grizzly bear attacks have doubled, and in some cases tripled according to statistics released by the province. In the years 2018-2019, there were 11 calls made about predatory grizzly bear attacks, and the following year there were 36 calls about attacks, according to the statistics. Through April 2023 -- the latest month statistics were released -- there were 29 calls about attacks. 

On Friday, officials urged the public to "take precautions in case of wildlife encounters, which includes carrying bear spray, traveling in groups, and ensuring pets are leashed." 

In:
• Bear
• Canada

Stephen Smith

Stephen Smith is a senior editor for CBSNews.com.