Thousands of fear-stricken people spent the night outdoors after a new earthquake killed dozens of people and spread more misery in Nepal.
The country is still reeling from a devastating quake that killed more than 8,000 nearly three weeks ago.
A US Marine Corps helicopter carrying six Marines and two Nepalese soldiers was reported missing while delivering disaster aid, although there have been no indications the aircraft crashed.
Home ministry official Laxmi Dhakal said today that army helicopters were scouring the Sunkhani area, nearly 50 miles north-east of Kathmandu, for the missing helicopter.
Yesterday's magnitude-7.3 quake, centred between Kathmandu and Mount Everest, struck hardest in the foothills of the Himalayas and triggered landslides that blocked roads to remote villages in several districts.
Most of the 65 people confirmed dead by this morning were in Dolakha district, located north-east of Kathmandu, the district's chief administrator Prem Lal Lamichane said.
"People are terrorised. Everyone is scared here. They spent the night out in the open," he said, adding the administration was running out of relief material.
He asked the government to send more helicopters and supplies, and said there were many injured people stranded in villages.
The new quake also left nearly 2,000 injured, according to the home ministry's latest count.
But that toll was expected to rise as reports trickled in of people in isolated Himalayan towns and villages being buried under rubble, according to the UN's Office for the Co-ordination of Humanitarian Affairs.
Tremors radiated across parts of Asia. In neighbouring India, at least 16 people were confirmed dead after rooftops or walls collapsed onto them, according to India's home ministry. Chinese media reported one death in Tibet.
The magnitude-7.8 earthquake that hit on April 25 killed more than 8,150 and flattened entire villages, leaving hundreds of thousands homeless in the country's worst-recorded quake since 1934.
The US Geological Survey said yesterday's earthquake was the largest aftershock so far.
Impoverished Nepal 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.
In Washington, Navy Captain Chris Sims said the missing Huey helicopter was conducting disaster relief operations near Charikot, Nepal.
A nearby Indian helicopter heard radio chatter about a possible fuel problem, said US Army Colonel Steve Warren. The Huey had dropped off supplies and was headed to a second site when contact was lost, he said, adding that there has been no smoke or other signs of a crash.
Due to the rugged terrain, the helicopter could have landed in an area where the crew was unable to get a beacon or radio signal out, he said.
Yesterday's quake was followed closely by at least 17 strong aftershocks, according to the USGS.
Frightened residents in the capital, who had returned to their homes only a few days ago, had to again set up tents to sleep in empty fields, car parks and on pavements.
"Everyone was saying the earthquakes are over ... Now I don't want to believe anyone," said 40-year-old produce vendor Ram Hari Sah.
Extra police 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 hit hardest on April 25, while previously damaged buildings collapsed with the latest quake.
Residents of the small town of Namche Bazaar, about 35 miles from the epicentre of yesterday's quake and well known to high-altitude trekkers, said a couple of buildings damaged earlier had collapsed there as well. However, there were no reports of deaths or injuries.
The earth also shook strongly in neighbouring Tibet, unleashing a landslide that killed one person and injured three, according to China Central Television.
Two houses collapsed, the state broadcaster said, quoting disaster officials of the regional Tibetan government.