There is mounting criticism of circumstances surrounding the recent accidental killing of a female black bear in Yellowstone National Park by rangers firing rubber bullets from a 12-gauge shotgun.

The 155-pound bear was killed in the northern part of the park, where it had charmed hundreds of visitors since late July while hanging around the Grand Loop Road.After receiving reports of visitors feeding a black bear, rangers shot the bear with rubber bullets to frighten it from the area. However, one of the bullets punctured the bear's lungs, officials said.