© AP Photo/Xinhua, Liu GuoqianIn this photo released by China's Xinhua News Agency, locals stand outside after a quake hit Kangding County in Sichuan Province, China Saturday, Nov. 22, 2014.
The U.S. Geological Survey said the magnitude-5.9 quake hit Saturday about 30 kilometers (20 miles) from the county of Kangding in Sichuan province. China's seismological agency put the magnitude at 6.3.
One person was also missing as of Sunday afternoon, according to a statement from the Ganzi prefecture government, which oversees Kangding.
The four dead included a woman in her 70s who was struck by a falling window pane, the official Xinhua News Agency and state broadcaster CCTV said, citing Chen Yunbing, a doctor at the region's Ganzi People's Hospital.
A stampede at a primary school in Tagong town during the quake injured 42 children, according to Xinhua.
Thirty homes collapsed and 2,630 others suffered serious damage, the Sichuan government information office said.
Western China is regularly hit by earthquakes, and reports said Saturday's quake could be felt in the Sichuan provincial capital of Chengdu on the plains below the Himalayan foothills. Sichuan was struck by a magnitude-7.9 quake in May 2008 that left nearly 90,000 people dead, many of them in collapsed schools and other poorly constructed buildings.
Construction standards have been significantly tightened since then, and the country's disaster response capacity has improved with better equipment and trained rescue teams.
As in Japan this quake has occurred in a mountainous area. Rocky ground is supposed to be better in an earthquake but it is not flexible. So the houses were not built to withstand an earthquake. Earthquakes do not kill but houses do.