Floods and landslides hit four districts in the North Sumatra province over the weekend, killing at least 20 people, according to the national disaster agency's tally.

The latest landslide hit a remote road in the Deli Serdang district of North Sumatra province on Tuesday following spells of torrential rain.

"As of today, seven people died from the landslide incident in the Sembahe (village)," Sariman Sitorus, a spokesman for the local search and rescue agency, told AFP.

Several of the dead were extracted from a tourist bus that passed through the area when the landslide occurred, he added.

Heavy equipment has been deployed to help with the search operation.

At least 16 people were injured by the landslide, Sariman said, citing data from a nearby hospital.

Indonesia is prone to landslides during the rainy season, typically between November and April, but some disasters caused by adverse weather have taken place outside that season in recent years.

In May, at least 67 people died after a mixture of ash, sand and pebbles carried down from the eruption of Mount Marapi in West Sumatra washed into residential areas, causing flash floods.