BACKPACKING -- Rangers have taken the rare step of capturing and killing a grizzly bear deemed a threat to human safety in Yellowstone National Park after the bruin menaced a hiker without any apparent provocation.

Bear managers told Reuters the 4-year-old male grizzly was euthanized on Monday, two days after the 258-pound animal charged at but did not injure a man sitting along a hiking trail near Yellowstone Lake.

Read on for more details from the Reuters report.

The encounter at Yellowstone Lake ended after the bear tore into a food-filled backpack the hiker threw at the animal.

The confrontation marked the latest in a string of incidents in which the same grizzly showed aggression toward people in its search for food at campgrounds and other developed areas in the park, officials said in a statement.

The greater Yellowstone area, encompassing parts of Wyoming, Idaho and Montana, is home to at least 600 grizzlies -- big, hump-shouldered bears listed as threatened under the U.S. Endangered Species Act.

The decision to euthanize the bear -- which happens at the park about once every three years -- came less than a month after a female grizzly attacked and killed a Yellowstone hiker it perceived as a threat to its two cubs.

The park did not capture or kill that grizzly because it had been acting in a purely defensive manner and had no previous history of conflicts with humans, officials said.

By contrast, the young male grizzly that charged the hiker over the weekend exhibited rare predatory behavior, Yellowstone spokesman Dan Hottle said.

He said most incidents in which grizzlies charge people are linked to mother bears protecting their young.

"This grizzly crossed that threshold and made direct and aggressive contact," Hottle said. "It will never be known if it was coming after (the man) for the food or to take him down."

Problems between grizzlies and people in the Northern Rockies reached unprecedented levels last year, with an estimated 75 bears killed in the region as a whole because of problem behavior like raiding chicken coops or trash bins or preying on livestock, government statistics showed.