China has deployed 2,500 soldiers to the south-western province of Yunnan to help search for survivors after an earthquake killed at least 398 people.
More than 1,800 people were injured when the magnitude 6.1 earthquake struck on Sunday.
Attempts to reach the epicentre have been hampered by heavy rain, with some rescuers forced to travel on foot.
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 joined more than 300 police and firefighters from Zhaotong and about 400 emergency workers and sniffer dogs from across Yunnan province in the rescue operation.
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 continuing landslides have left many roads in the region too damaged to use, she adds.
Firefighters managed to rescue 32 people, including a five-year-old boy, who had been trapped inside a residential block, the official Xinhua news agency reports.
Bodies pulled out of collapsed buildings in Longtoushan, the epicentre of the earthquake, were laid out in the street wrapped in blankets or planks of wood, AFP reports.
Premier Li Keqiang has travelled to the area to oversee the rescue operation. According to AFP, quoting Xinhua, he had to walk for "over three miles" (5km) to reach the worst-hit village in Yunnan on Monday.
Xinhua said its reporters in Ludian county - which includes Longtoushan - "saw drenched survivors sit along the muddy roads waiting for food and medication. Some half-naked survivors were quivering in the rain".
Equipment brought to the area included life-detection instruments and digging equipment to help with rescue efforts.
At least 12,000 houses were reportedly destroyed in the earthquake, with another 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.
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.
Are you in Yunnan or the neighbouring provinces? Have you been affected by the earthquake? You can share your experiences by emailing firstname.lastname@example.org using the subject line " Yunnan earthquake".