A moderately strong earthquake that left 25 dead in southwestern China displaced nearly half the county's people and raised questions among experts Friday about whether structures had been built to code.
More than 3,600 houses were destroyed and 11,300 badly damaged after Thursday's earthquake struck a mountainous area in Yunnan province, near the border with Myanmar, the Civil Affairs Ministry said on its website. Parts of a supermarket and a hotel also buckled and fell.
More than 127,000 of Yingjiang county's 300,000 people have been displaced by the temblor which Chinese authorities measured at a magnitude 5.8.
Search efforts continued Friday but the chances of finding more people alive were shrinking, said Jin Guangwei, an official from the Yunnan disaster relief center. Officials were now focusing on treating the injured, relocating survivors and distributing relief materials, he said.
"Many of the buildings in the area were constructed with low earthquake resistance and so they fell easily," Jin said.
Unsafe construction is a chronic problem in China and is often blamed on poor planning, shoddy work or the theft of materials. The deaths of many students whose schools collapsed during a catastrophic earthquake in Sichuan province in 2008 triggered complaints from parents and others who accused builders of cutting corners to increase profits.
The Civil Affairs Ministry said 25 people were killed in Yingjiang, while another 250 people were injured — 134 of them seriously. The official Xinhua News Agency said the central government has allocated 55 million yuan ($8.4 million) to the region for quake relief.
Survivors spent the night in tents while seven aftershocks measuring up to 4.7 in magnitude shook the town, state media reported. CCTV showed people eating meals cooked in large pots over portable stoves in the morning next to tents set up in a public square.
The buildings in Yingjiang, in quake-prone Yunnan, should have been constructed to resist earthquakes much stronger than Thursday's, said Wang Yayong, a chief engineering adviser at the Chinese Academy of Building Research in Beijing.
If the seismic building codes had been strictly followed, "or if they had made any conscious effort at all to strengthen the houses, then the houses should not have just collapsed like that," Wang said.
However, Wang also noted that the shallow depth of the quake, which struck from six miles (10 kilometers) below the surface, did exacerbate its impact. "It means that the earthquake is very close and has catastrophic impact on the ground."
Many of the injured were being treated by medical staff on a basketball court outside Yingjiang county's overcrowded hospital, CCTV footage showed. People with bandaged heads sat in chairs and were hooked up to intravenous drips, while others lay on blankets on the ground.
There was no word Friday from authorities across the border in Myanmar.
The Myanmar Meteorological Department released a statement Thursday saying a quake had hit 230 miles (370 kilometers) northeast of Mandalay. The statement did not mention injuries or damage. Authorities in the tightly ruled country tend not to immediately discuss the effects of natural disasters.
More than 1,000 soldiers have been sent to aid in rescue efforts while thousands of tents, quilts and coats were being sent from the central government, state media said.
Xinhua said the quake-prone region has been hit by more than 1,000 minor tremors over the past two months.