The death toll from two earthquakes in China's western Gansu province has climbed to 89, with more than 500 people severely injured, after 1,200 buildings collapsed and tens of thousands more were badly damaged, the official Xinhua news agency said.
The quakes hit eight towns in the remote and mountainous Minxian and Zhangxian counties, about 105 miles (170 kilometres) south-east of the provincial capital, Lanzhou, from 7.45am on Monday (12.45am BST), Xinhua said.
"Many have been injured by collapsed houses," said a Minxian county doctor surnamed Du. "Many villagers have gone to local hospitals along the roads."
More than 1,200 houses had collapsed and another 21,000 were severely damaged, Xinhua said.
On Monday the government of the city of Dingxi, the worst-affected area, said more than 27,000 people were left homeless.
Photos posted on Chinese social media showed roads on the sides of riverbanks had subsided and farmhouses reduced to piles of red bricks. There were also power cuts, and mobile phone and internet coverage was disrupted.
Xinhua said about 3,000 police and rescue personnel had been sent to the quake-hit region, though landslides and flooding had hampered their efforts, and officials said they were concerned more rain could exacerbate the need for shelter.
The US Geological Survey reported two earthquakes, the first at a 5.9 magnitude and a strong aftershock about an hour and a half later at a 5.6 magnitude. Chinese authorities reported the first quake was a 6.6 magnitude.
Xinhua said that by Monday evening 422 aftershocks had been recorded, with the strongest measuring 5.6 in magnitude, citing Chang Zhengguo, a spokesman for the Gansu provincial government.
Gansu borders Sichuan province, where a 6.6 quake in April killed 164 people and injured more than 6,700, China's worst quake in three years. That quake hit close to where a devastating 7.9 temblor killed some 70,000 people in May 2008.