The landslide and floods caused by torrential rain hit residential areas near Lake Toba on the western island of Sumatra late on Friday, killing a 78-year-old woman and forcing the evacuation of scores of residents.

Eleven people were initially declared missing but rescuers found another body today, Budiono, the head of Medan search and rescue agency said in a statement.

Children aged six and eight years old are among the missing, said Budiono, who like many Indonesians goes by one name.

The search is split between the water and land, with several boats and divers scouring for the missing while excavations and scouting on shore around Lake Toba are also underway, he said.

Searchers were also using sonar detection, fearing bodies may have been dragged into the world’s biggest volcanic lake, Budiono said.

Around 140 people were evacuated from the village, according to national search and rescue agency Basarnas.

Indonesia is prone to landslides during its 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 on a remote Indonesian island triggered by heavy rains in March killed scores of residents in a village and buried houses under mud and debris.