An assistant sub-inspector of Calcutta police on election duty in Sikkim was mauled by a Himalayan black bear early on Friday near Gangtok.

Rash Behari Adhikari, 56, was rushed to STNM Hospital in Gangtok and later shifted to the North Bengal Medical College and Hospital in Siliguri. A colleague from Calcutta who is in Sikkim on poll duty said Adhikari has received 90 stitches.

The bear attacked the officer when he stepped out of his camp to relieve himself. “I was taking a walk around 7am when I heard shouts. When I reached the spot, I found a policeman lying injured. At a distance I saw a bear almost 8ft in height running into a bush. I called my friends and we took the injured to hospital,” said Sameer Subba, a Sikkim policeman.

Doctors said the bear had injured Adhikari on the face and the right thigh. “He had to be shifted to Siliguri as we failed to stop the bleeding,” said a hospital official.

More than 3,000 cops from Calcutta are deployed across Sikkim for the Assembly and Lok Sabha polls, to be held on Saturday. Adhikari belongs to one of the two companies sent from Calcutta Armed Police. An officer at Lalbazar said arrangements are being made to bring him back to Calcutta on Saturday.

N.T. Bhutia, the divisional forest officer in East Sikkim district, said: “A team of more than 10 foresters, armed with tranquillisers, is searching for the Himalayan black bear. Residents have been alerted.” The animal, he added, might have strayed out of the Bhushuk forest, near Gangtok, in search of food.

The Himalayan black bear is an endangered species under the Wildlife Protection Act. If the animal is deemed to be dangerous to human lives, forest guards can shoot it down with permission of the state chief wildlife warden, said a wildlife department official.

Such attacks have been reported from Sikkim earlier, too. In August 2011, a Himalayan black bear had to be shot in East Sikkim after it attacked a woman near a maize field. In December 2012, a bear attacked a Border Roads Organisation worker near Gangtok and left him with a broken nose.