Rain and landslides are hampering the search for survivors of a 6.9 magnitude earthquake in an isolated Himalayan region stretching across India, Nepal and Tibet.
At least 53 people have died and many more injured since Sunday when the quake struck. The epicentre was in India's mountainous Sikkim state, where at least 18 people have died, the BBC reports.
At least five people were killed in Nepal, police say, and at least seven died in Tibet, China's official Xinhua news agency reported. At least six other people were killed in other Indian states.
Officials in all regions say the death toll is likely to rise as rescuers reach the remote mountainous areas struck by the quake.
The quake struck at 6.10pm local time, according to the US Geological Survey, and was followed by two strong aftershocks.
Telephone lines were knocked out across the state, while power cuts plunged the capital Gangtok into darkness. Hundreds of people spent the night on the streets after buildings developed cracks, reports say.
Tremors were felt in the north-eastern Indian states of Assam, Meghalaya, and Tripura. They were also felt in regions of India: West Bengal, Bihar, Jharkhand, Uttar Pradesh, Rajasthan, Chandigarh and Delhi. Bangladesh and Bhutan also felt the quake.