A powerful earthquake struck Nepal and sent tremors through northern India on Saturday, killing more than 1,100 people, touching off a deadly avalanche on Mount Everest and toppling a 19th-century tower in the capital Kathmandu.
There were reports of devastation in outlying, isolated mountainous areas after the midday quake of magnitude 7.9, Nepal's worst in 81 years, centered 50 miles (80 km) east of the second city, Pokhara.
As fears grew of a humanitarian disaster in the impoverished Himalayan nation of 28 million, an overwhelmed government appealed for foreign help. India was first to respond by sending in military aircraft with medical equipment and relief teams.
A police official said the death toll in Nepal alone had reached 1,170, more than half of them in the Kathmandu Valley. A further 36 fatalities were reported in northern India, 12 in Chinese Tibet and four in Bangladesh.
The quake was more destructive for being shallow, toppling buildings, opening gaping cracks in roads and sending people scurrying into the open as aftershocks rattled their damaged homes.
Indian tourist Devyani Pant was in a Kathmandu coffee shop with friends when "suddenly the tables started trembling and paintings on the wall fell on the ground.
"I screamed and rushed outside," she told Reuters by telephone from the capital, where at least 300 people died.
"We are now collecting bodies and rushing the injured to the ambulance. We are being forced to pile several bodies one above the other to fit them in," reports Reuters.
BBC reports Media caption Minister Minendra Rijai says there has been "massive damage" around the epicentre of the quake
Rescuers are digging through the rubble of collapsed buildings in the capital trying to reach survivors.
A number of historic buildings have been destroyed.
Among those wrecked was the landmark Dharahara tower, with many feared trapped in its ruins.
After the earthquake struck, frightened residents came out into the streets. Mobile phones and other communications have been disrupted.
Kathmandu's landmark Dharahara tower before and after the earthquake
Analysis: Navin Singh Khadka, BBC Nepali
Major historic monuments in the Nepalese capital have been destroyed in the powerful earthquake, eyewitnesses and officials have said.
These include a nine-storey tower, temples and some parts of what was once a royal palace, all listed as Unesco world heritage sites.
Pictures posted on social media show some of the monuments have been reduced to rubble.
Eyewitnesses say several others now have cracks and could collapse.
Officials have said some temples and monuments at other world heritage sites near Kathmandu have also been damaged.
These sites are Nepal's major tourist attractions.
Nepal had lost several such monuments during a major earthquake in 1934.
There are also reports of damage to Kathmandu airport which could hamper relief operations.
With little known about the extent of the damage around the earthquake's epicentre, there are fears the death toll could rise.
Rescuers are searching through rubble for survivors
Historic landmarks were wrecked in the earthquake
Aftershocks continued to ripple through the region hours later.
The quake triggered an avalanche on Mount Everest, killing at least eight people, and another five in Tibet, officials and reports say.
"Running for life from my tent. Unhurt. Many many people up the mountain," tweeted mountaineer Alex Gavan.
World's deadliest recent earthquakes
Iran, 2003: More than 26,000 people killed in 6.6 earthquake near the city of Bam
Indonesia, 2004: Devastating 9.1 earthquake and ensuing tsunami off the Sumatran province of Aceh kills more that 230,000 people in a dozen countries
Pakistani-administered Kashmir, 2005: 7.6 earthquake near Muzafferabad kills about 100,000 people
China, 2008: Nearly 90,000 killed in 7.9 earthquake in eastern Sichuan province
Haiti, 2010: More than 220,000 people killed in 7.0 magnitude earthquake
At least 35 people have been killed in India, Indian officials say, with one death also reported in Bangladesh.
Indian Prime Minister Narendra Modi has met his ministers to review the situation. Pakistan's Prime Minister, Nawaz Sharif, has pledged help for the Nepalese authorities.
It is the worst earthquake to strike Nepal since one in 1934 all but destroyed Kathmandu.
There are fears the death toll could rise once the scale of devastation becomes clear.