BEIJING — More than 140 people in southwestern China are feared to have been buried under an avalanche of mud and rocks when a hillside collapsed on Saturday, Chinese news media reported.

The landslide struck Xinmo, a village in Sichuan Province, early in the morning. Although the number of possible deaths remained unclear, officials estimated that 40 homes appeared to have been engulfed, Sichuan Online, a provincial news agency, reported. At that hour, many residents would probably have been in their homes.

Xinhua, the official news agency, said that 141 people were missing. The Communist Party secretary of Sichuan, Wang Dongming, and other officials were rushing to the village, in a sign of the gravity of the disaster, Sichuan Daily said.

Li Yuanjun, a local official who arrived in the village shortly after the slide, said he saw near total devastation. “In the entire village I could only see one home,” Mr. Li told the Sichuan Daily. “The rest had been totally buried by rocks.”