BEIJING — A magnitude 6.3 earthquake struck southwestern China on Sunday, killing at least 175 people in a remote mountainous area of Yunnan province, causing some buildings, including a school, to collapse.

An estimated 180 people are missing and 1,400 are injured, officials said. The U.S. Geological Survey said the quake registered at a shallow depth of less than 1 mile. Chinese state media said was felt most strongly Yunnan, as well as in the neighboring provinces of Guizhou and Sichuan.

The official Xinhua news agency said that the epicenter was in Longtoushan town in Yunnan's Ludian county.

Communications have been seriously affected and rescuers are rushing to the scene, the report said.

Pictures posted online by state media showed troops stretchering people away, and bricks which had fallen off buildings damaging cars.

Many people rushed out of buildings onto the street after the quake hit, electricity supplies were cut and at least one school collapsed, Xinhua added.

The government is sending 2,000 tents, 3,000 folding beds, 3,000 quilts and 3,000 coats to the disaster zone, the report said.

Ludian is home to some 265,900 people, Xinhua added.

China is frequently struck by quakes in this part of the country. A quake in Sichuan in 2008 killed almost 70,000 people.