ITANAGAR, India — A 7.8-magnitude earthquake hit Nepal on Saturday, causing widespread fatalities, chaos in the streets, damage to historic temples and homes, and avalanches atop Mount Everest, authorities said.

Casualties reports varied as rescuers worked frantically to free victims from the rubble. Hundreds of injured people filled hospitals both the capital of Kathmandu and around the quake’s epicenter of Lamjung, about 40 miles from the capital. According to the Associated Press, the death toll is more than 900 across four countries, with 876 reported dead in Nepal alone.

India’s Home Affairs Ministry said 18 people were confirmed dead in states in Northern India — Uttar Pradesh, Bihar and West Bengal — with casualties also reported in China’s autonomous region of Tibet and Bangladesh. The shocks from the violent temblor — which struck shortly before noon — was felt throughout South Asia, as far away as Dhaka and Lahore.

Several buildings collapsed in the historic heart of Kathmandu in the seconds following the quake, including Dharahara Tower, the iconic landmark built in 1832 that was a UNESCO heritage site. “There’s nothing left,” one despairing survivor from that neighborhood told CNN-IBN, the Indian news channel.

In Kathmandu, residents said they were staying outside their homes, afraid to go inside, and still feeling the aftershocks hours after the initial quake, which was originally reported as 7.9 magnitude. More than a dozen aftershocks were recorded, some at magnitude 5.5 or greater. Dozens of patients began flooding the city’s hospitals from neighboring areas, and damaged roads were clogged with traffic, hindering relief efforts.

“The influx is so huge, it’s difficult to cope with the pressure,” said Chakra Raj Pandey, the head of Grande International Hospital, one of the city’s largest private medical facilities. “The government is not really prepared. We are getting no help or guidance from them. We are shocked. We don’t know what the days ahead will be like. The first day, few hours we are suffering so much. What will happen later?”

Pandey said that his hospital has seen at many as 10 dead so far, with more than 100 casualties suffering abdominal, head and chest injuries. The hospital is running short on essential supplies, such as adrenaline and oxygen, and medicines needed for patients in intensive care, he said. Patients have crowded into the large grounds of the hospital, waiting hours for treatment.

“Many are crying. Many are hungry,” Pandey said. “We haven’t had any water for hours.”

When the quake hit just before noon, there was a complete sense of panic in the streets and people ran out of their homes “holding each other … terrified,” said Yubaraj Ghimire, editor of the Annapurna Post.

Ghimire said that in quake’s immediate aftermath, even doctors fled from their hospitals and clinics in fear.

“I have heard of people going to the hospital with injuries, but the doctors were not there,” Ghimire said. “The doctors were also panic-stricken and had left the buildings.”

The earthquake was the worst in Nepal in decades; the country suffered a devastating earthquake in 1934, when thousands died.

The U.S. Geological Survey said the quake hit at 11:56 a.m. in Lamjung and was considered a “shallow quake,” which can be worse than deeper tremors. It was the largest shallow quake since the 8.2 temblor off the coast of Chile on April 1, 2014.

Avalanches were reported on world’s highest peak, Mount Everest, with government officials saying that at least 30 people have been injured on the mountain so far and eight climbers believed dead.

“Running for life from my tent,” climber named Alex Gaven tweeted. “Many people up the mountain.”

Neighboring India mobilized two military relief planes to the devastated region about 4 p.m. Saturday, as well as relief and medical teams, and began evacuating Indian tourists. Sitanshu Kar, a representative for the Indian ministry of defense, tweeted that India has deployed two C-17s, two MI-17 helicopters and a C-130 with rescue personnel and medical supplies.