Washington (AFP) - At least one grizzly bear is thought to have killed and partially eaten a hiker in America's famed Yellowstone National Park, authorities said.

The National Park Service said the man's body was found Friday and though the exact cause of death had not been determined, he had defensive wounds on his forearms.

"Based on partial tracks found at the scene, it appears that an adult female grizzly and at least one cub... were present and likely involved in the incident," the park service said in a statement Saturday.

The man was from Montana and was a long-term seasonal employee of Medcor, a company that runs three health clinics in the Wyoming park.

He was reported missing Friday morning when he did not show up for work. The victim's body had been partially devoured and "cached" -- or covered -- near Lake Village, officials said.

Wildlife biologists have set bear traps in the area and if any captured beasts are identified as having been involved in the attack, they will be killed.

"We may not be able to conclusively determine the circumstances of this bear attack, but we will not risk public safety," said Yellowstone National Park Superintendent Dan Wenk.