At least 18 people were killed and five others were missing after flash floods and a landslide on the Indonesian island of Sumatra, a local official said Saturday in a new toll.

Torrential rains triggered the floods and landslide that hit Pesisir Selatan regency in West Sumatra province, forcing around 46,000 people to evacuate to temporary shelters.

"Eighteen people were found dead. Five were missing," Pesisir Selatan disaster mitigation agency acting head Doni Gusrizal told AFP late Saturday.

The official updated the toll from 10 he gave in an earlier statement.

Doni said debris from the disasters had hampered ongoing rescue efforts.

"The impact from the floods (was) extraordinary. Currently we are cleaning the road... Our vehicles cannot pass through," he said.

As of late Saturday, electricity services were still down in several parts of Pesisir Selatan after the disaster, according to an AFP reporter in the regency.

At least 14 houses were buried in the landslide, more than 20,000 houses were flooded and eight bridges had collapsed, according to earlier statement from the national disaster mitigation agency.

In Padang Pariaman regency, also in West Sumatra, heavy downpours between Thursday and Friday caused rivers to overflow and triggered floods and a landslide, killing at least three people, according to a statement from the local disaster mitigation agency.

Indonesia is prone to landslides during the rainy season and the problem has been aggravated in some places by deforestation, with prolonged torrential rain causing flooding in some areas of the archipelago nation.

A landslide and floods swept away dozens of houses and destroyed a hotel near Lake Toba on Sumatra in December, killing at least two people.