Nepal's Home Ministry says the death toll from the devastating earthquake has reached 1805.
Nearly 1,400 people have been killed in a 7.8 earthquake that has devastated Nepal
The latest toll puts the overall regional fatalities at 1865.
Home Ministry official Laxmi Dhakal said on Sunday that at least 4,700 people have been injured in Saturday's magnitude 7.8 earthquake.
But the final toll from the 7.8 magnitude quake on Saturday could be much higher, and dozens more people were reported killed in neighbouring India and China.
Offers of help poured in from governments around the world, with the US and EU announcing they were sending in disaster response teams, as emergency workers fanned out across Nepal to rescue those trapped under collapsed homes and buildings.
Nepal police spokesman Kamal Singh Bam told AFP deaths have been reported from all regions except the far west.
"All our security personnel have been deployed to rescue and assist those in need."
The Red Cross said it was concerned about the fate of rural villages close to the epicentre of the quake northwest of the capital Kathmandu, where a historic tower collapsed.
"Roads have been damaged or blocked by landslides and communication lines are down preventing us from reaching local Red Cross branches to get accurate information," said IFRC Asia/Pacific director Jagan Chapagain.
At least 10 people were killed when an avalanche buried parts of Mount Everest's base camp in Nepal where hundreds of mountaineers have gathered at the start of the annual climbing season, officials said.
Google executive Dan Fredinburg was the only climber killed so far identified.
Lawrence You, director of privacy at Google, said Fredinburg was with three other Google employees, who all survived. He added that Google.org was contributing $US1 million to response efforts.
Experienced mountaineers said panic erupted at base camp, which had been "severely damaged", while one described the avalanche as "huge".
Gyanendra Kumar Shrestha, an official in Nepal's tourism department, told AFP: "We are trying to assess how many are injured. There might be over 1,000 people there right now, including foreign climbers and Nepalese supporting staff."
Kathmandu was severely damaged, and the historic nine-storey Dharahara tower, a major tourist attraction, was among buildings brought down.
At least a dozen bodies were taken away from the ruins of the 19th-century tower, according to an AFP photographer who saw similar scenes of multiple casualties throughout the city.
At least 42 people have died in India, including 30 in the eastern state of Bihar, while buildings in the capital New Delhi had to be evacuated.
China's official Xinhua news agency said 13 people were killed in the Tibet region.
The United States Geological Survey said the shallow quake - initially measured at 7.5 magnitude and later adjusted to 7.8 - struck 77km northwest of Kathmandu.
The quake ripped through the middle of highways in the capital and also caused damage to the country's only international airport, which was briefly closed.
Aftershock tremors could be felt more than two hours after the initial quake.
Nepal and the rest of the Himalayas are particularly prone to earthquakes because of the collision of the Indian and Eurasia plates.
A spokesman for Nepal's home ministry said the government had released around $US500 million as emergency funds for rescue operations.
The US Agency for International Development said a disaster response was being flown to Nepal and that the Obama administration had authorised an initial $1 million "to address immediate needs".
Britain, Germany, Norway, Spain and Israel have also pledged support and assistance.
