Nine people have been confirmed dead and more than 43 people were injured after two massive earthquakes jolted northwest China's Gansu Province on Saturday.
Rescuers are trying to reach four people still trapped in a cave that collapsed in the quakes, according to the Ministry of Civil Affairs.
And six of the dozens injured in the disaster-hit area are in a serious condition.
Over 10,000 homes have been destroyed, leaving their occupants exposed to temperatures that can fall below freezing, according to Gansu provincial seismological bureau.
Two thousand tents have been transported to the area to aid the homeless.
Quakes of magnitude 6.1 and 5.8 on the Richter scale hit most areas in Minle County and Shandan County of the city of Zhangye on Saturday at 20:41 and 20:48 respectively, the seismological bureau said.
And 170 minor aftershocks had followed as of 12:30 Sunday, but caused no serious damage. The State Seismological Bureau in Beijing said the most severe aftershock registered 4.0 on the Richter scale.
Almost a third of homes were damaged in the hardest hit regions in Gansu Province. Ninety percent of Yangzaizi Village of Yugong Township in Minle County has been destroyed.
The disaster areas have experienced snow and below freezing temperatures in recent days, with the mercury plunging as low as -6 C.
A total of 7,454 families in Minle County have been affected by the quakes. Some of the homeless took shelter in wheat stacks overnight before the tents arrived.
The powerful quakes also threatened the safety of two dams, creating 5-centimetre-wide cracks in the walls of Shuangshushi reservoir in Minle County.
Another reservoir in Quzhaizi of Minle County also developed a crack 1-centimetre-wide and 410-meters-long.
The two reservoirs started to release water at 21:00 on Saturday.
A report from Minle County said water and heating supplies were cut off.
Premier Wen Jiabao and Vice-Premier Hui Liangyu have ordered a "quick and full'' response by the Ministry of Civil Affairs and asked the army to assist. A team led by the disaster relief center of the Ministry of Civil Affairs is working with provincial departments to supervise rescue operations on the ground.
Relief materials are being organized and will be moved to the area with the help of the army in Lanzhou.
The experts from the provincial seismological bureau said a fault in the northern ranges of Qilian Mountains may have caused the massive tremors. The area is on a seismic belt in the Hexi or Gansu Corridor in northwestern Gansu Province.
The region suffered its most severe earthquake, registering 7.25 on the Richter scale, in 1954. That quake, centered on Shandan County, killed 50 and wounded 300.
This is not the first major earthquake in China this year. Earlier this month, an earthquake with a magnitude of 6.1 stuck Dayao County in southwest China's Yunan Province, another seismic area. It killed at least three people, injured 38 and destroyed at least 12,156 rooms in people's homes.
A total of 590,000 people were affected.
But the deadliest earthquake in China this year hit an area near Kashgar in northwestern Xinjiang Uygur Autonomous Region on February 24, killing 24 and injuring 268.
(China Daily October 27, 2003)