GANGTOK, India (AP) — Thousands of terrified survivors of a Himalayan earthquake that killed 81 people and rattled parts of India, Nepal and China crowded Tuesday into shelters and relatives’ homes or stayed out in the open for fear of aftershocks.

Soldiers used dynamite and earthmovers to clear landslides on highways through the steep valleys linking the worst-hit northeastern Indian state of Sikkim to the rest of India. They managed to clear a path to Mangan, closest to the epicenter of Sunday’s 6.9-magnitude quake, but many other communities remained cut off and authorities fear the death toll could rise once rescuers reach them.

Indian army helicopters ferried rescuers and dropped food and supplies to still-inaccessible villages in Sikkim, a sparsely populated and almost entirely mountainous region that was an independent protectorate before becoming an Indian state in 1975.

Residents of the state, which borders Nepal, Bangladesh, Bhutan and the Chinese region of Tibet, have been spooked by at least five aftershocks since Sunday, with the strongest a magnitude 5.3.

Thousands of others moved out of their homes in Gangtok and the neighboring villages and took shelter in the open grounds of a university.