NEW DELHI — The vegetable markets, streetside dumpling stands and other signs of ordinary life slowly returning to Nepal were violently interrupted Tuesday when another powerful earthquake shook the eastern part of the country less than three weeks after a deadly earthquake left most of it flattened.
Loose hillsides and cracked buildings gave way and collapsed when a 7.3 magnitude earthquake struck shortly after noon about 50 miles east of Kathmandu, the capital, near the China border.
Residents and office workers ran screaming into the streets, and people described plumes of mud and clouds of dust rising up as cracked structures fell. Prakash Banjara, an engineering student, was on an aid mission, delivering rice to villages in Sindhupalchok District, when “the earth started shaking so violently.”
“The mountains before my eyes started tumbling down in massive landslides,” Mr. Banjara said by telephone. He begged for help for his small group of volunteers, stranded by landslides on an isolated road, unable to contact the police.
“We are clinging together on the road, hoping the clouds will go away,” he said. “I saw buildings crumble as we made our way here. Maybe there are people trapped in them. We have no way of knowing yet.”
By early Wednesday, Nepal’s National Emergency Operation Center had reported 65 deaths and 1,988 injuries from Tuesday’s earthquake. The death toll from the April 25 quake, with a magnitude of 7.8, had reached 8,159 and was expected to rise.
Jasmine Avgerakis, who is stationed in Sindhupalchok with the charity Mercy Corps, said she had watched people overcome the trauma of the first earthquake, roll up their sleeves and set about cleaning up. “They were just starting to go home and feel comfortable there,” she said.
Tuesday’s quake, Ms. Avgerakis said, brought “the sight of panic.”
“Children were crying,” she continued. “Seeing them run from their homes to this field, there was just so much fear in their faces. They had been starting to move on slightly, in areas that had the means to.” With the new earthquake, she said, “they went back to the pain again.”
The largest cluster of casualties — 34 dead and 101 seriously injured — was registered in the district of Dolakha, a mountainous and sparsely populated region where the elevation reaches just under 24,000 feet. Seventy-seven people in Dolakha died in the April 25 earthquake, officials said.
Gajendra Thakur, who oversees relief work for the district, described conditions in Dolakha as “very, very severe.”
Susan E. Hough, a seismologist at the United States Geological Survey, said it was “not a surprise by any means” that a major aftershock followed the April quake, though the one Tuesday was somewhat larger than typical. A rule of thumb is that the largest aftershock of an earthquake is about one magnitude smaller.
The quakes occurred in the collision zone where the Indian subcontinent is being pushed under the Eurasian tectonic plate. Forces that are building up in the Himalayas also let loose big earthquakes when the faults break and slide.
People across Nepal had feared another powerful quake for weeks, in part because the first one left many buildings unstable, and many people refused to sleep indoors for more than a week. A vast number of buildings appear too dangerous even to enter, with ground floors buckling outward and deep cracks running up their facades. There have also been a number of aftershocks and minor quakes.
An American structural engineer who examined buildings in Bhaktapur, an ancient pink-brick city near Kathmandu, said he believed a third of the buildings he had seen would have to be razed.
Ranveig Tveitnes, the deputy leader of the Norwegian Red Cross team in the hard-hit city of Chautara, said many of the houses in town that had survived the first earthquake collapsed entirely on Tuesday, and the road through town that had been painstakingly cleared of debris was again blocked by rubble.
Ms. Tveitnes said doctors at the mobile Red Cross hospital who had transitioned to treating everyday illnesses went back to setting bones and trauma surgery.
Search-and-rescue teams, including international ones that had been preparing to leave, began digging through the rubble looking for survivors. Bharat Shrestha, who was participating in rescue work in a town about seven miles west of Chautara, said the efforts began while the earth was still rumbling from aftershocks. “I can still see massive clouds of mud and dust around, as massive landslides continue to happen,” he said. “Concrete houses in Chautara have crumbled, and the main road leading to Chautara is completely blocked with debris.”
Even before Tuesday’s earthquake, aid workers worried that wealthy nations seemed unwilling to fund the relief effort in Nepal, having pledged only about 15 percent of the initial appeal for $423 million, said Jamie McGoldrick, the resident coordinator for the United Nations in Nepal.
“The international community seems quite reluctant to provide material,” he said.
On Tuesday, panic spread throughout Kathmandu, snarling traffic and jamming phone lines, but the number of building collapses was not as catastrophic as some had feared. Four guesthouses collapsed in the city’s Gongabu neighborhood, a popular stopping point for migrant laborers waiting for flights to the Persian Gulf states or Malaysia, said Kamal Singh Bam, a police spokesman. He said people were presumed dead inside.
Kunda Dixit, the editor of The Nepali Times, said the tremor “just became bigger and bigger and bigger, started rocking more and more and more.” He said that office workers had run into the street and that electric power was out.
“It started slow, it kept on swaying, and the birds were up in the air,” he said. “I looked outside, and the electricity poles were just swaying from side to side. The wires were swaying.”
Video footage taken at the airport in Kathmandu showed hundreds of people rushing for the exits. Madhu Prasad Regmi, the secretary of Nepal’s Election Commission, which is based in the capital, said workers had rushed out onto the street and remained unwilling to return to their desks four hours later.
“The fear on people’s faces is very visible,” he said.
CCTV, China’s state-run broadcaster, reported that one person had been killed and two injured in a landslide in Gyirong County, Tibet, that was triggered by the earthquake. Eight people also died in the Indian state of Bihar, which borders eastern Nepal, officials said.
The country’s exhaustion was evident in a message sent via a government Twitter account about two hours after the earthquake. “Pray to Almighty: Keep all Nepalese safe in this difficult period of time,” read the message, sent from the Nepal Emergency Operations Center.