Rescue efforts in Nepal are intensifying after more than 1,800 people were killed in the country’s worst earthquake in more than 80 years.Many countries and international charities have offered aid to Nepal to deal with the disaster.

Seventeen people have been killed on Mount Everest by avalanches – the mountain’s worst-ever disaster.

Officials fear that the death toll could rise as the desperate search for survivors continues.

Scores of bodies have been ferried to hospitals in 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.

The 7.8 magnitude quake struck an area of central Nepal between the capital, Kathmandu, and the city of Pokhara on Saturday morning.

Helicopters began landing at Mount Everest base camp on Sunday to rescue avalanche victims.

There were also victims in India, Bangladesh and in the Chinese region of Tibet.

Little information has emerged from the epicentre, where extensive damage has been reported, and there are fears the death toll could rise yet further.

It is the worst earthquake to strike Nepal since one in 1934 which killed some 8,500 people.

‘Moment of crisis’

“We have launched a massive rescue and rehabilitation action plan and lots needs to be done,” Information and Broadcasting Minister Minendra Rijal told Indian television.

“Our country is in a moment of crisis and we will require tremendous support and aid.”

Scores of people slept outside on Saturday night – braving wet and cold weather – either because their homes were destroyed or because they feared numerous aftershocks.

World leaders and global charities have offered emergency aid to Nepal, as the government grapples with the scale of the disaster.

Its task is made harder because internet and mobile phone communications are erratic, with many roads closed due to quake damage.

The United States, China, Pakistan and European Union countries are among those who have pledged aid as has India, which is at the forefront of the relief effort.

The US Embassy in Nepal pledged $1m (£660,000) in initial aid while the US Agency for International Development sent an urban search and rescue team.

“We are working closely with the government of Nepal to provide assistance and support,” said Secretary of State John Kerry.

China on Sunday dispatched a 62-member search and rescue team.

Epicentre of the quake

A number of international charities including Red Cross, Oxfam, Doctors Without Borders and Christian Aid are also sending teams to quake-hit areas.

“We do not yet know the scope of the damage, but this could be one of the deadliest and most devastating earthquakes since the 1934 tremor which devastated Nepal and [the Indian state of] Bihar,” said International Federation of the Red Cross and Red Crescent Societies (IFRC) Asia-Pacific Director Jagan Chapagain.

The IFRC said it was especially worried about the fate of villages near the epicentre of the quake, some 80km (50 miles) from the capital Kathmandu.

In Europe, Britain, Germany and Spain pledged assistance, with Norway pledging $3.9m in humanitarian aid.

“The absolute priority must be to reach people who are trapped and injured, and provide shelter and protection to those who have lost their homes,” UK International Development Secretary Justine Greening said.

Foreign climbers and their Nepalese guides around Mount Everest were caught by the tremors and a huge avalanche.

As well as the 17 confirmed deaths, 61 people were injured when part of the base camp was buried under snow.

Helicopters trying to airlift the injured to Kathmandu were delayed by cloudy weather, but have now managed to land at the base camp.

Dan Fredinburg, a Google executive who described himself as an adventurer, has also been killed, Google confirmed.

Offers of aid:

• The US is sending a disaster response team and has released an initial $1m (£0.7m) according to the US aid agency USAid
• India has sent several aircraft, carrying medical supplies and a mobile hospital, as well as a 40-strong disaster response team, including rescuers with dogs
• The UK is sending an eight-strong team of humanitarian experts
• Pakistan is sending four C-130 aircraft carrying a 30-bed field hospital and army doctors and specialists; urban search-and-rescue teams equipped with radars and sniffer dogs; and food items, including 2,000 meals, 200 tents and 600 blankets
• Norway has promised 30 million krone (£2.5m; $3.9m) in humanitarian assistance
• Germany, Spain, France, Israel and the European Union are also pledging to send aid

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 than 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