The 12 people were still missing and believed to have been buried by the landslide, Parulian Nasution, secretary of the South Tapanuli Regency Administration, stated here on Friday.
"Last night, the entire team held a coordination meeting to conduct the evacuation this morning. The fate of all (missing victims) is not yet known," he remarked.
The search and rescue operations were being conducted by a joint team comprising personnel of the military, police, local disaster mitigation office, and volunteers.
The landslide was triggered by incessant heavy rains on Thursday, he stated.
Based on the available information, the missing people, included nine members of two families and three employees of the Shyno Hydro power plant project. The employees comprised two Indonesians and one Chinese national.
The landslide originated from a cliff measuring 50 meters high and 50 meters wide.
The project's spokesperson, Lolinta, confirmed about the natural disaster while adding that information was yet awaited on the chronology of events in the incident.