China has sent 2,500 soldiers to the south-west province of Yunnan after an earthquake killed hundreds of people.
At least 398 people died and more than 1,800 were injured when the magnitude 6.1 earthquake struck on Sunday.
Chinese troops with life-detection instruments and digging equipment are on their way to the region to help with rescue efforts.
State broadcaster CCTV said the earthquake was the strongest to hit the mountainous province in 14 years.
President Xi Jinping called for "all-out efforts" to find survivors as he dispatched soldiers to the area.
They will join more than 300 police and firefighters from Zhaotong and about 400 emergency workers and sniffer dogs from across Yunnan province in the rescue operation.
Premier Li Keqiang was also heading to the area, Xinhua news agency said.
Xinhua reported that 12,000 houses had been destroyed and about 30,000 damaged.
The government had sent 2,000 tents, 3,000 folding beds, 3,000 quilts and 3,000 coats to the disaster zone, Xinhua said.
But rescuers trying to deliver the much-needed supplies are struggling to reach the area, reports the BBC's Celia Hatton in Beijing.
Unrelenting rain and persisting landslides have left many roads in the region too damaged to use, she adds.
Chen Wangchang, head of Ludian County hospital in Yunnan's Zhaotong City, said temporary tented medical facilities had been set up.
"All the houses had already collapsed when we arrived. Dead bodies were everywhere and there were a lot of injured people."
The US Geological Survey (USGS) said the focus of the earthquake was at a relatively shallow depth of 10km (six miles) below the Zhaotong region, in the north-east of the province.
It hit at 16:30 local time (08:30 GMT) on Sunday.
State television broadcast footage of people fleeing their homes after the earthquake, which knocked out electricity supplies and communication lines in the region.
"The walls of several buildings crumbled, and water pipes were ruptured," one local resident wrote on Weibo, China's Twitter-like service.
Another local told Xinhua that the streets there were like a "battlefield after bombardment", adding that her neighbour's house, a new two-storey building, had collapsed.
A spokesman for UN chief Ban Ki-moon said the secretary-general was "saddened by the loss of life" while the White House offered its condolences and said the US "stands ready to assist."
South-west China lies in an area that is prone to earthquakes.
An earthquake in Sichuan in 2008 killed tens of thousands of people while a magnitude 7.7 quake in Yunnan in 1970 killed at least 15,000.
JUSTCLICK & CONNECT