Over 400 people trapped by rubble in the earthquake-stricken Tibet were rescued, officials in China said on Wednesday. The epicenter of Tuesday's magnitude 6.8 quake, one of the region's most powerful tremors in recent years, was located in Tingri in China's Tibet, about 50 miles north of Mount Everest, the world's highest mountain. It also shook buildings in neighboring Nepal, Bhutan and India.

The quake was so strong that part of the terrain at and around the epicenter slipped as much as 5.2 feet over a distance of 50 miles, according to an analysis by the United States Geological Survey. Twenty-four hours after the temblor struck, those trapped under rubble would have endured a night in sub-zero temperatures, adding to the pressure on rescuers looking for survivors in an area the size of Cambodia.

Temperatures in the high-altitude region dropped as low as minus 0 degrees Fahrenheit overnight. People trapped or those without shelter are at risk of rapid hypothermia and may only be able to live for five to 10 hours even if uninjured, experts say.

At least 126 people were known to have been killed and 188 injured on the Tibetan side, state broadcaster CCTV reported. No deaths have been reported in Nepal or elsewhere.

Chinese authorities have yet to announce how many people are still missing. In Nepal, an official told Reuters the quake destroyed a school building in a village near Mount Everest, which straddles the Nepali-Tibetan border. No one was inside at the time.

German climber Jost Kobusch said he was just above the Everest base camp on the Nepali side when the quake struck. His tent shook violently and he saw several avalanches crash down. He was unscathed.

“I’m climbing Everest in the winter by myself and...looks like basically I’m the only mountaineer there, in the base camp there’s nobody,” Kobusch told Reuters in a video call.

His expedition organizing company, Satori Adventure, said Kobusch had left the base camp and was descending to Namche Bazaar on Wednesday on the way to Kathmandu.

But in Tibet, the damage was extensive.

An initial survey showed 3,609 homes had been destroyed in the Shigatse region, home to 800,000 people, state media reported late on Tuesday. Over 1,800 emergency rescue personnel and 1,600 soldiers had been deployed.

Footage broadcast on CCTV showed families huddled in rows of blue and green tents quickly erected by soldiers and aid workers in settlements surrounding the epicenter, where hundreds of aftershocks have been recorded.

State media said over 30,000 people affected by the quake had been relocated.