"More cotton-padded tents are badly in need," the official Xinhua News Agency reported from Gansu province, where two earthquakes that hit minutes apart Saturday killed nine people and injured dozens. Hundreds of houses collapsed in several rural villages.
"Most of the quake victims are now huddling in makeshift shelters in jolted areas," Xinhua said, adding that the temperature is routinely below freezing at night.
The government said preliminary figures show a potential economic loss of $37.4 million, which includes damage to more than 46,000 households in 175 villages. Xinhua said 14,322 houses were flattened and more than 16,000 head of livestock were killed or injured.
Top officials from the provincial Civil Affairs Bureau in Lanzhou arrived in Yongle County on Monday morning to oversee delivery of 220 cotton-padded tents. Other tents and shelter materials reached Shandan County, another severely hit area, but thousands more were needed.
"Thousands homeless in subzero temperatures," said the Web site of the Communist Party newspaper People's Daily.
About 1,000 more tents shipped from south-central China's Hunan province were on the way, Xinhua said.
The twin quakes, with magnitudes of 6.1 and 5.8, rumbled through the region Saturday night.
In Yaozhai village, the hardest-hit area, more than 2,000 villagers each got a single share of instant noodles for breakfast Monday. More relief food was due to arrive later Monday, Xinhua said.
The government said the water levels of two reservoirs affected by the earthquakes were "under safety lines" Monday. Authorities discharged water late Saturday and on Sunday to "guarantee the safety of local people and property" below the reservoirs, Xinhua said.
Several farmers' fields were flooded by the discharge but no one was injured, according to Tian Baozhong, mayor of the city of Zhangye, near the affected area.
The water reduction from the Shuangshusi and Zhaizhaizi reservoirs began after cracks were spotted in two dams. Nearly 200 million cubic feet of water were released, the central government said.
Premier Wen Jiabao has ordered a "quick and full" response by the government, which has earmarked $843,000 for initial relief efforts. Urgently topping the list: Water and power-supply facilities, some of which were damaged by the tremors and multiple aftershocks.
The three affected counties are located in an earthquake-prone region called the Qilian seismic zone, where a mountain range of the same name bumps up against flatlands. Government seismologists say a rupture in that range may be making the area more seismically active.
A magnitude 8.5 quake on the edge of that zone in 1920 killed 200,000 people, according to Zhang Xiaodong of the State Seismological Bureau's analysis and forecast center. In 1954, a magnitude 7.3 quake in the zone rumbled through Shandan County, killing 50 people.
By Ted Anthony