At least 50 people died and about 150 were injured Friday after two earthquakes hit a mountainous area of south-western China within an hour, also forcing the evacuation of 100,000 people, dpa reported.
Officials in Yiliang county, Yunnan province, reported at least 49 dead and more than 150 injured, while at least one person died in nearby Zhaotong city, which administers Yiliang, the provincial government said.
Premier Wen Jiabao was en route to oversee relief work in the area, which is some 1,700 kilometres south-west of Beijing, state broadcaster China Central Television reported.
The International Red Cross said it was sending assessors and initial relief aid through its local offices.
State media quoted an official in Zhaotong as saying the death toll could rise as rescue workers reached remote villages, some of which were cut off by landslides.
The first 5.7-magnitude tremor was felt across a wide area of neighbouring Yunnan, Guizhou and Sichuan provinces at 11:19 am (0319 GMT), the China Earthquake Administration reported on its website.
A 5.6-magnitude quake with an almost identical epicentre hit the same area at 12:16 pm.
The epicentre of the first quake was about 15 kilometres from Yiliang county town, while the second epicentre was just 5 kilometres from the town, the administration said.
The quakes affected some 700,000 people in Zhaotong's Zhaoyang district, Yiliang and neighbouring Daguan county.
The provincial civil affairs bureau said more than 100,000 people were evacuated after the quakes damaged or destroyed some 20,000 houses.
Francis Markus, a regional spokesman for the International Red Cross, said the mountainous terrain would pose "logistical challenges" to relief operations.
"The areas in both Yunnan and Guizhou are partly inhabited by the Yi ethnic minority and are officially classified as among the poorest counties," Markus said.
"Many of the homes are built of timber and mud, which makes them more likely to collapse under the impact of this shallow earthquake," he said.
The quakes destroyed at last three homes and damaged more than 1,500 others in Guizhou's Weining county, but no deaths and only one injury were reported, the official Xinhua news agency said.
"The hardest part of the rescue now is traffic. Roads are blocked and rescuers have to climb the mountains to reach hard-hit villages," the agency quoted Li Fuchun, the head of Weining's Luozehe township, as saying.
The agency said many people had rushed outdoors after the first quake shook buildings in Zhaotong city, which is about 30 kilometres from the epicentre.
The tremors were also felt in Leshan city in Sichuan province, it quoted a local resident as saying.
Yunnan provincial officials despatched 6,000 tents, water, food clothing and other emergency supplies to Yiliang, reports said.
At least 16 aftershocks hit the area.