After being initially treated at the local medical facility, he was airlifted to the military hospital in Delhi, the official said.
Colonel D.K. Acharya was attacked in the residential quarters late on Thursday night when he was passing by. When he raised alarm, Armymen on sentry duty rushed to his rescue after which the bear ran away in the wilderness.
He has sustained serious injuries, sources said. A forest official of the neighbouring Nanda Devi national park, T.S. Sai, said a team is combing the thickets nearby and that patrolling has been increased in the area.
(With inputs from agencies.)