Rescue efforts in Nepal are intensifying after at least 2000 people were killed in the country's worst earthquake in more than 80 years.
Officials fear the death toll could rise as the desperate search for survivors continues.
Many countries and international charities have offered aid to Nepal to deal with the disaster.
The shallow 7.8 quake struck at midday (local time) on Saturday in central Nepal, about 81 kilometres northwest of the capital Kathmandu. It caused massive damage in the Kathmandu Valley.
Victims have also been reported in India, Bangladesh, Tibet and on Mt Everest.
A strong earthquake aftershock struck India and Nepal tonight, shaking buildings in New Delhi and triggering an avalanche in the Himalayas. The United States Geological Survey said the tremor was 6.7 magnitude.
Over a third of Nepal's 75 districts have suffered severe damage, and some villages close to the epicentre have had 80 percent of the houses destroyed. In some cases, whole villages are reported to have been buried by landslides.
Australian authorities are trying to contact hundreds of their people, with about 350 still not confirmed as safe.
Desperate rescue efforts underway
The death toll could rise, as the situation is unclear in remote areas which remain cut off or hard to access.
Many mountain roads are cracked or blocked by landslides.
Scores of bodies have been ferried to hospitals in the capital Kathmandu, many of which are struggling to cope with the number of injured.
More than 700 have died in the capital alone.
Medics are expecting a fresh influx of patients on Sunday as supplies run low.
Rescuers in places used their bare hands to dig for survivors still buried underneath piles of rubble and debris overnight on Saturday.
Army officer Santosh Nepal told the Reuters news agency that he and his soldiers had to dig a passage into a collapsed three-storey residential building in Kathmandu using pickaxes because bulldozers could not get through the ancient city's narrow streets.
"We believe there are still people trapped inside," he told Reuters.
Many historic buildings in the capital, including the Darahara Tower, have been destroyed.
Kunda Dixit, who edits the Nepali Times, said the earthquake created so much thick dust he thought Kathmandu had been completely destroyed.
He told Radio New Zealand National's Sunday Morning that he was on a retreat with other journalists on a mountain overlooking the city when the quake struck.
"It was so violent that the jolt - I felt like the whole mountain had moved about a metre and a half northward," he said.
"Then we looked down at the city and just couldn't believe our eyes. It was shrouded in dust. It was like a dust storm. We were convinced, actually, that the whole city had been destroyed."
Mr Dixit said about 200,000 people left homeless by the quake were sleeping in tents overnight in very cold conditions.
Immediately after the quake, residents came out into the streets of Kathmandu, with mobile phone networks and other communications disrupted.
Bodies recovered after avalanche
Seventeen bodies have been recovered after an avalanche triggered by the earthquake buried part of Mt Everest's Base Camp sparking fears for hundreds of climbers on the mountain.
The Mountaineering Association said it was the worst disaster ever on the mountain.
It said a further 61 people were injured and the first rescue helicopters had only now been able to get in to fly them to a medical centre.
There are 100 climbers at Everest Camps One and Two above base camp and all are safe, according to the Mountaineering Association.
But it said it will be difficult to evacuate them because the Icefall Route back to Everest Base Camp was damaged.
It is the start of the main climbing season and officials estimate at least 1000 climbers including 400 foreigners were either at Base Camp or up the mountain when the quake struck.
God gives us another chance to live- pic @AfzanizamHamzah. Malaysian at the #Everest BC @501Awani pic.twitter.com/RgongtyICU
— Rizal Zulkapli AWANI (@rizalzulkapli) April 25, 2015
About 150 New Zealanders are confirmed as safe in Nepal.
But Foreign Affairs Minister Murray McCully said communication problems were hampering efforts to clarify how many more New Zealanders were unaccounted for.
One New Zealander in Kathmandu, Prue Smith, described the experience as frightening and said people around her were injured by falling bricks.
"We saw cracks emerging in the walls surrounding us - rubble was falling down."
If is safe for you to share your story, you can reach Radio New Zealand by emailing iwitness@radionz.co.nz. If you have concerns about a New Zealand citizen family member in Nepal, please contact MFAT on 04 439 8000.
Aid pledged
Kathamandu airport has re-opened and aid flights have started delivering desperately needed supplies.
The US has said it is sending a disaster response team to Nepal and has released an initial $US1m to address immediate needs, according to US aid agency USAid.
Indian air force planes have landed with 43 tonnes of relief material, including tents and food, and nearly 200 rescuers.
Pakistan's Prime Minister Nawaz Sharif has pledged help for the Nepalese authorities.
UK Prime Minister David Cameron said the UK "will do all" it can to help in the aftermath of the earthquake, and French President Francois Hollande said France was ready to respond to any request for aid and assistance.
New Zealand Prime Minister John Key said the Government is to contribute $1 million aid, but may consider further funds. He said New Zealand offered a search and rescue team, but at this stage Nepal has indicated it would prefer to use teams from countries which were closer neighbours.
Major loss of life in #NepalEarthquake, with lives also lost in #India. Major international support will be needed. https://t.co/0KHckrJWBf
— Helen Clark (@HelenClarkUNDP) April 25, 2015
At least 35 people have been killed in India, according to reports, with one death also reported in Bangladesh.
It is the worst earthquake to strike Nepal since one in 1934 which killed some 8500 people.
How likely is this kind of earthquake?
Yesterday's devastating earthquake, which has killed hundreds and caused widespread damage is a relatively rare event, according to the US Geological Survey.
Here is its take on what happened:
Source: US Geological Survey
- BBC / Reuters