At least nine people were confirmed dead in the predawn disaster in southwest Yunnan, with dozens still missing.

Rescuers in China have stepped up efforts to find dozens of people buried in a landslide in southwest Yunnan.

The landslide shook two villages in the mountainous Zhengxiong county in the early hours of Monday morning as many people were sleeping, burying 18 houses and at least 47 people.

According to state broadcaster CCTV, at least nine people were found dead, two were rescued from the rubble and taken to hospital.

“The mountain just collapsed, dozens were buried,” a witness named Gu told state television.

He said four of his relatives were among the rubble.

“They were all sleeping in their houses,” he said.

State news agency Xinhua said rescue workers were in a “race against time” to find the missing people after a night of freezing temperatures.

Chinese President Xi Jinping has ordered “comprehensive” rescue measures.

The agency quoted Wu Junyao, director of the Zhaotong Natural Resources and Planning Bureau, which includes the affected villages, as saying the disaster was “the result of a collapse in the steep cliff area at the top of the slope.”

Hundreds of rescue workers, including soldiers, were sent to the area known for its steep, rugged mountains that are covered in snow in winter. The two affected villages were built at the foot of the mountains and more than 500 residents were evacuated after the disaster.

State media showed rescuers climbing over concrete blocks and collapsed, snow-covered roofs to find survivors.

Luo Dongmei was sleeping when the landslide struck.

“I was sleeping, but my brother knocked on the door and woke me up. They said there was a landslide and the bed was shaking, so they rushed upstairs and woke us up,” Luo, 35, told The Associated Press.

Luo, her husband and three children were evacuated to a school along with many other residents.

Luo said she was unable to contact her sister and aunt, who lived closer to the site of the landslide. “The only thing I can do is wait,” she said.

According to the National Meteorological Center, Yunnan is one of several provinces in China currently experiencing bitterly cold temperatures.

Last week, rescuers evacuated tourists from a remote ski resort in northwest China where dozens of avalanches triggered by heavy snow had trapped more than 1,000 people for a week. The avalanches blocked roads and stranded both tourists and residents of a village in the Xinjiang region near China’s border with Mongolia, Russia and Kazakhstan.

There was no immediate official explanation as to what may have caused Monday’s landslide. Zhengxiong County is located about 2,250 km (1,400 miles) southwest of Beijing, with elevations up to 2,400 meters (7,900 feet).

Landslides, often caused by rain or unsafe construction, are not uncommon in China.

At least 70 people died in landslides last year, including more than 50 in an open-cast mine in the Inner Mongolia region.