A female grizzly bear attacked and killed a man while he was hiking with his wife in Yellowstone National Park in the US state of Montana yesterday.
The fatal mauling happened after the couple came across the bear and here cubs near the start of the Wapiti Lake trail.
A National Park Service statement said the couple had inadvertently surprised the mother and her cubs, and in "an attempt to defend a perceived threat to her cubs, the bear attacked and fatally wounded the man".
Another group of hikers nearby heard the victim's wife crying out for help and used a mobile phone to call park rangers for assistance.
The victim's identity has been withheld pending notification of other family members.
The bears involved yesterday’s encounter have not been captured, and park officials said they did not immediately have enough information to determine what measures, if any, they might take in the aftermath of the attack.
Initial information indicated the mother bear behaved normally in defending her cubs and would not be killed as a result of her actions, park spokeswoman Linda Miller said.
However, bears found to have had repeated run-ins with park visitors are sometimes relocated.
"If we have an aggressive bear that continually poses a threat to human safety, then we work to remove it from the ecosystem," Yellowstone spokesman Al Nash said, adding he did not know if this grizzly had any previous human encounters.
Attacks by bears are extremely rare. No visitors were injured by bears in Yellowstone during all of last year, and yesterday's incident marked the first bear-caused human death in the park since 1986, the Park Service said.
A mother grizzly killed one man and injured two other people in an unusual night-time attack on sleeping campers just outside Yellowstone in Montana last July. The bear involved in that incident was later trapped and destroyed because the attacks were considered to be unprovoked and predatory.
A bear warning sign is posted at the start of the Wapiti Lake trail because it is an access point to the Pelican Valley area known for significant bear activity.
Reuters