Dozens of people have been killed and hundreds injured in a powerful earthquake in rural areas of China's south-western province of Sichuan.
The 6.6-magnitude quake wrecked buildings, cut power and blocked roads in Lushan county, killing more than 100 and injuring hundreds, officials say.
Rescuers are struggling to get through to the worst-affected areas because of aftershocks and landslides.
Tens of thousands were killed in a quake that hit Sichuan in 2008.
The latest quake, initially reported as of 7.0 magnitude, struck at 08:02 local time (00:02 GMT).
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Its epicentre was in a rural area some 115km (70 miles) west of provincial capital Chengdu, according to the US Geological Survey (USGS).
State broadcaster CCTV showed images of injured people being taken to hospital in Lushan.
One injured man told the channel: "We still live in our old house, the new one is not ready yet. Our house just collapsed. Everything collapsed."
The quake was measured at 12km below the surface, a shallow depth that usually indicates extensive damage.
Aerial shots of Lushan showed buildings collapsed or without roofs.
Power has been lost in the area, water supplies have been cut and telephone lines are also down. People in Chengdu felt the tremor and came running into the streets wrapped in blankets.
Chengdu resident Aaron Ozment told the BBC there was huge confusion in the city.
"I threw on a some clothes quickly and made my way into the courtyard of my complex," he said.
"Making calls was almost impossible; everybody was trying to contact everybody they knew."
Residents in the nearest city to the epicentre, Ya'an, felt jolts from the quake and aftershocks, but the city does not appear to have suffered major damage.
State news agency Xinhua said more than 6,000 soldiers had been despatched to help with rescue efforts.
Premier Li Keqiang is travelling to Sichuan to oversee the operation.
"The current most urgent issue is grasping the first 24 hours since the quake's occurrence, the golden time for saving lives," Mr Li was quoted as saying by Xinhua.
The 2008 disaster in Sichuan left five million people homelesChina Earthquake: Dozens Killed, 600 Injured
An earthquake strikes Sichuan province leaving dozens of people dead and hundreds injured, Chinese media says
At least 56 people have died and over 600 injured after an earthquake struck China's southwestern province of Sichuan, Chinese media says.
The quake, measured at varying magnitudes between 6.6 and 7.0, hit at 8.02am local time close to the city of Ya'an in Lushan county and the epicentre had a depth of 8 miles (13km), Xinhua reported.
It set off landslides, destroyed buildings and has triggered a major rescue operation involving 2,000 troops.
The quake was felt strongly by residents in neighbouring provinces and in the provincial capital city of Chengdu, causing many to rush outside, according to accounts on China's Weibo microblogging service.
A resident in Chengdu said he was on the 13th floor of a building when he felt the quake. The building shook for about 20 seconds and he saw tiles fall from nearby buildings.
The quake struck close to where a massive tremor occured in 2008, killing 68,000 people.
Sky's Asia Correspondent Mark Stone said: "The huge earthquake in 2008 was magnitude 7.9 and at a depth of 12 miles. This latest quake has smaller magnitude and depth, but it is still very much a concern for people in Sichuan."
Local seismologists registered the quake at magnitude 7.0 while the US Geological Survey (USGS) gave it as 6.6.
USGS said that "significant" casualties were likely and that "extensive damage i
Twin tremors in neighbouring Yunnan province last September triggered landslides that left at least 80 people dead.
A magnitude-5.5 quake in Yunnan last June killed four people and injured more than 100.
Another 5.4 tremor the year before near the border with Burma left 25 people dead and injured 250.raw footage - CHINA Earthquakeraw footage - CHINA Earthquakeraw footage - CHINA Earthquakeraw footage - CHINA Earthquakeraw footage - CHINA Earthquakeraw footage - CHINA Earthquakeraw footage - CHINA Earthquakeraw footage - CHINA Earthquakeraw footage - CHINA Earthquakeraw footage - CHINA Earthquakeraw footage - CHINA Earthquake
