Two separate landslides triggered by torrential rain in western Indonesia have killed at least nine people, including four geothermal workers, and left 17 others missing, officials said Sunday.

Disaster official Ade Edward said 20 houses were buried by mud and rocks that fell from surrounding hills at dawn Sunday in Tanjung Sani village in West Sumatra province's Agam district. Rescuers recovered five bodies and were searching for 17 people who reportedly were buried under the mud, he said. Three injured villagers were being treated at a hospital.

Heavy rain also triggered a landslide late Saturday in a drilling field owned by PT. Pertamina Geothermal Energy, killing four workers on Sumatra island, company official Adiatma Sardjito said.

"The workers were having dinner when the landslide suddenly occurred," Sardjito said, adding that five others were injured and one was missing.

He said the company had sent heavy equipment to assist efforts to retrieve the bodies.

Seasonal downpours cause frequent landslides and flashfloods each year in Indonesia, a chain of 17,000 islands where millions of people live in mountainous areas or near fertile flood plains.