The toll from the 7.8-magnitude earthquake, which struck at 0611 UTC Saturday, has passed 1,200, according to police. In Kathmandu, the capital of the nation of 27.8 million, the earthquake brought down the UNESCO-recognized 19th-century nine-story Dharahara tower. Aftershocks continued for over two hours.

"Deaths have been reported from all regions except the far west," Nepal police spokesman Kamal Singh Bam told the news agency AFP on Saturday.

Most died when the buildings they were in collapsed. Hospitals are reportedly overflowing with injuries.

"This is a very large earthquake in a significantly populated region with infrastructure that has been damaged in past earthquakes," US Geological Survey seismologist Paul Earle told the Associated Press.

A Washington Post journalist posted before and after photos of the destruction on Twitter.

Prime Minister Sushil Koirala, attending a summit in Jakarta, had tried to rush back home but made it as far as Bangkok, where he found his connecting flight to Kathmandu canceled because the airport had been shut down. Service has been restored to take in relief flights, but commercial travel remains stalled.

India reported dozens killed. At least 13 have died in China. Tremors reached Pakistan and Bangladesh.

Officials also say 10 people died when an avalanche buried parts of Mount Everest's base camp in Nepal, where hundreds of mountaineers had gathered for the start of the annual climbing season.

"We don't have the details yet, but 10 have been reported dead so far, including foreign climbers," Gyanendra Kumar Shrestha, an official in Nepal's tourism department, told the news agency AFP on Saturday. "We are trying to assess how many are injured."

Searchers fanned out across Nepal to rescue those trapped under collapsed homes, buildings and other debris. Offers of help have poured in from governments around the world, with the United States and EU announcing that they would send in disaster response teams, and Germany pledging aid, as well. Officials for the Red Cross have expressed concern about the fate of rural villages close to the epicenter of the quake that struck 11 kilometers (7 miles) underground 77 kilometers northwest of Kathmandu.

Nepal sits where the Eurasian and Indian tectonic plates collide. A similar quake in 1934 killed 17,000. In 2011, dozens in China, India and Nepal died in a 6.8-magnitude earthquake.

A rogue snowstorm last fall killed dozens of trekkers in Nepal. More than 100 people died in a series of landslides just two months before that.

mkg/rc (Reuters, AFP, dpa, AP)