Intense rainfall on Monday in a mountainous area near Pekalongan city in Central Java province sparked the landslide, collapsing bridges and burying cars and houses.

"Per this morning, we have found 21 victims who died, and there are five more who are still being searched," Budiono, head of the search and rescue agency from nearby city Semarang, who like many Indonesians goes by one name, told AFP.

Heavy equipment has been deployed to the worst-hit Kasimpar village to search through the remains of the house of a local official as well as a cafe where more victims are thought to have been buried as they sought shelter from the rain.

"We are focusing on those two spots and the nearby river. Victims might have been carried to the river because of the current," said Budiono.

At least 13 people were also injured in the landslide, according to search and rescue agency Basarnas.

The rescuers have started to clean the thick mud and debris from the roads, Budiono said.

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.

Climate change has also increased the intensity of storms, leading to heavier rains, flash floods and stronger gusts.

In May, at least 67 people died after heavy rains caused flash floods in West Sumatra, pushing a mixture of ash, sand, and pebbles from the eruption of Mount Marapi into residential areas.