At least 26 people have died with 11 more reported missing after flash floods and landslides on the Indonesian island of Sumatra.

Rescuers recovered more bodies as waters began to recede following torrential rains, officials said on Monday.

Monsoon rains and rising rivers submerged nine districts and cities in West Sumatra province since Thursday.

On Friday, a major mudslide caused a river to breach its banks and tear through mountainside villages in the Pesisir Selatan district.

Indonesia Floods
In an image made from video, soldiers ride motor bikes in a village affected by flash flood in Langgai, West Sumatra (AP)

Relief efforts have been hampered by power outages, damaged bridges and roads blocked by thick mud and debris, the National Disaster Management Agency said.

Agency spokesperson Abdul Muhari said rescuers recovered more bodies, mostly in the worst-hit villages in Pesisir Selatan and its neighbouring Padang Pariaman district, bringing the death toll to 26.

Landslides buried at least 14 houses, he said. At least two villagers were injured and rescuers were still searching for 11 people reportedly missing.

Monsoon rains in West Sumatra province have submerged more than 37,000 houses and buildings, Mr Muhari said. At least three houses were swept away by flash floods and 666 others were damaged.

The agency said floods had damaged 26 bridges, 45 mosques and 25 schools, destroying 13 roads and two irrigation system units, which submerged rice fields and plantation.

Heavy rains cause frequent landslides and flash floods in Indonesia, an archipelago nation of more than 17,000 islands where millions of people live in mountainous areas or near floodplains.