As many as 75 people were killed and 21,000 houses were damaged Monday when an earthquake rocked China's Gansu province, authorities said.
Total 73 people in Dingxi city and two in its neighbouring Longnan city have been killed in the 6.6-magnitude quake that struck at 7.45 a.m.
Fourteen people are missing from Minxian county which was hit hard, reported Xinhua.
The epicentre of the quake was at a depth of 20 km, the China Earthquake Networks Centre said.
A staggering 411 aftershocks have been recorded in the quake-hit region, with the strongest measuring 5.6 in magnitude, Chang Zhengguo, spokesman for the provincial government, said at a press conference in the provincial capital of Lanzhou.
Initial assessment showed that the quake had caused the collapse of more than 1,200 houses and severe damage to 21,000 homes, he added.
Two helicopters and about 3,000 armed police, firefighters, local militiamen and government staff have been sent to the quake-hit region to help with the rescue efforts.
Xinhua reported that buildings in rural areas have been reduced to ruins and others developed cracks in the walls.
A total of 31 people were confirmed dead in Meichuan, according to rescuers.
Zhu Wenqing, a 40-year-old farmer in Majiagou village, said his house survived the first quake but eventually collapsed following seven or eight aftershocks.
Villagers said the victims were mainly the elderly and children, as most failed to escape from collapsing houses.
Communication in many villages around Meichuan township and in 13 towns of Zhangxian county has been cut off.
The earthquake happened at a fault zone in the province, which has recorded 25 earthquakes with a magnitude of over 5.0 throughout history, the China Earthquake Administration said.
The strongest quake recorded around the fault zone measured 8.0 in magnitude on July 21, 1654. That one happened about 120 km from the site of the latest quake, it added.
Locals said the quake Monday morning lasted for about one minute.
The tremors were also felt in Tianshui city and Lanzhou as well as the cities of Xi'an, Baoji and Xianyang in neighbouring Shaanxi province.