At least 157 people have been killed and thousands more injured in an earthquake in China's south-western province of Sichuan.
The 6.6-magnitude tremor wrecked buildings and cut power in Lushan county, near the site of a previous earthquake five years ago, which claimed nearly 100,000 lives.
The death toll was likely to rise over coming days, officials said, with aftershocks and landslides hampering rescue efforts in the worst-affected areas.
The quake struck shortly after 8am local time (00:02 BST), with its epicentre in the steep hills of rural Lushan county, 110 kilometres west of the provincial capital, Chengdu.
Buildings, many of them older structures, were levelled, with walls collapsing and tiles sliding from roofs.
State broadcaster CCTV showed scenes of confusion in the immediate aftermath of the tremor, with survivors rushing into the streets, many in their nightclothes or wrapped in blankets.
"I threw on some clothes quickly and made my way into the courtyard of my complex," said local resident Aaron Ozment. "Making calls was almost impossible; everybody was trying to contact everybody they knew."
The quake was measured close to the surface, with a depth of just 12km, meaning its force was more destructive.
An estimated 10,000 houses were damaged throughout the county, with the village of Longmen completely flattened.
Remote areas of the province remained unreachable by road, with phone and power lines down and water supplies cut.
Aerial photos of Lushan showed houses in ruins, villages flattened and roofs lying in rubble.
The city nearest to the epicentre, Ya'an, appeared not to have suffered major damage, though residents reported feeling jolts from the quake and aftershocks.
The quake rattled buildings as far away as Chengdu, 115km to the east, state news agency Xinhua reported, forcing the closure of the city's airport.
2,000 soldiers have been despatched to help with rescue efforts, Xinhua said.
Premier Li Keqiang flew to Sichuan to direct the rescue operation. "The current most urgent issue is grasping the first 24 hours since the quake's occurrence, the golden time for saving lives," Li said.
The 2008 disaster, which struck along the same Longmenshan fault, measured 7.9-magnitude, leaving more than 90,000 people dead, and five million people homeless. Many bodies were never recovered.