A major earthquake has hit a remote mountain region of Nepal, killing at least 37 people and triggering landslides and toppling buildings less than three weeks after the Himalayan nation was ravaged by its worst quake in decades.
The magnitude-7.3 quake - centred midway between the capital of Kathmandu and Mount Everest - hit hardest in districts north east of the capital.
It terrified a nation already shell-shocked and struggling after a more powerful quake on April 25 killed more than 8,150 and flattened entire villages, leaving hundreds of thousands homeless.
Information was slow to reach Kathmandu after the latest tremor but officials expected the death toll to rise as reports arrived of people being buried under rubble, according to the UN's Office for the Coordination of Humanitarian Affairs.
Nepal's Home Ministry reported at least 42 deaths but later lowered the toll to 37. It said at least 1,139 people had been injured in Nepal.
In neighbouring India, at least 16 people were confirmed dead after rooftops or walls collapsed on to them, according to India's Home Ministry. Chinese media reported one death in Tibet.
In Nepal, at least three people were rescued in the capital, while another nine were pulled to safety in the district of Dolkha, the government said.
Rescue helicopters were sent to mountain districts where landslides and collapsed buildings may have buried people, the government said. Home Ministry official Laxmi Dhakal said the Sindhupalchowk and Dolkha districts were the worst hit.
Search parties fanned out to look for survivors in the wreckage of collapsed buildings in Sindhulpalchowk's town of Chautara, which had become a hub for humanitarian aid after the magnitude-7.8 earthquake on April 25, Nepal's worst-recorded quake since 1934.
Nepal was left reeling by the April 25 tremor. The impoverished country appealed for billions of pounds in aid from foreign nations, as well as medical experts to treat the wounded and helicopters to ferry food and temporary shelters to hundreds of thousands left homeless amid unseasonal rains.
The new quake was deeper, coming from a depth of 11.5 miles, compared with the earlier one at 9.3 miles. Shallow earthquakes tend to cause more damage.
The latest event was followed closely by at least 10 strong aftershocks, according to the US Geological Survey.
Early reports indicated at least two buildings had collapsed in Kathmandu, although at least one had been unoccupied due to damage it sustained during the April 25 quake. Experts say that tremor caused extensive structural damage even in buildings that did not topple, and that many could be in danger of collapse.
Frightened residents in the capital, who had returned to their homes only a few days ago, are again setting up tents outdoors with plans to sleep in empty fields, car parks and on pavements.
Extra police officers were sent to patrol ad-hoc camping areas, while drinking water and extra tents were being provided, according to Kathmandu administrator Ek Narayan Aryal.
Meanwhile, new landslides blocked mountain roads in the district of Gorkha, one of the regions most damaged by the April 25 quake, while previously damaged buildings collapsed with the latest quake.
Residents of the small town of Namche Bazaar, about 35 miles from the epicentre of the new quake and a well-known spot for high-altitude trekkers, said a couple of buildings damaged in the earlier earthquake had collapsed. However, there were no reports of deaths or injuries in the town.
The earth also shook strongly across the border in Tibet, unleashing a landslide that killed one person and injured three, according to China's state broadcaster China Central Television. Two houses also collapsed, CCTV said, quoting the disaster relief headquarters of the regional Tibetan government.