Rescuers recover 20 bodies from flash floods and landslides on Indonesia's Sumatra island

caused mud and rocks to tumble down mountainsides, officials said Tuesday.

Torrential rains over the weekend caused rivers to burst their banks in four hilly districts in North Sumatra province, washing away houses and destroying farms.

Four more bodies were recovered Monday evening in Karo Regency, bringing the total there to 10, National Disaster Management Agency spokesperson Abdul Muhari said in a statement Tuesday.

Flash floods also left four people dead in Deli Serdang district, and rescue workers were still searching for two people who were swept away.

Earlier, rescuers recovered two bodies in villages in South Tapanuli district, and four members of a family, including two children, in Harang Julu, a mountainside village in Padang Lawas district.

Seasonal rain from about October to March frequently causes flooding and landslides in Indonesia, an archipelago of 17,000 islands where millions of people live in mountainous areas or near fertile flood plains.