About 40 homes were destroyed in Xinmo village in Maoxian county, after the side of a mountain collapsed at about 06:00 local time (22:00 GMT Friday), according to the BBC.
Rescue teams are frantically searching for survivors trapped beneath rocks.
Pictures posted by the People’s Daily newspaper show bulldozers moving earth and large boulders as the rescue effort continues.
A couple and a baby were rescued and taken to hospital after teams of workers used ropes to move large rocks while dozens of others searched the rubble, AFP news agency reports, citing local authorities.
The landslide blocked a two-kilometre (1.2-mile) stretch of a river, Xinhua news agency reports, citing local officials.
Local police told state broadcaster CCTV the landslide had been triggered by recent heavy rains in the region and that the situation was made worse by a lack of vegetation in the area.
“There are several tonnes of rock,” police captain Chen Tiebo told the broadcaster, adding: “It’s a seismic area here.”
Roads in the county were closed on Saturday to all traffic except emergency services, the news agency said.