Eruptions at Indonesia's Mt Sinabung have sent massive clouds of ash over nearby villages.
On Sunday, a 2,460 metre hot cloud hovered over residential areas, sparking police to evactuate two villages, Pintu Besi and Jeraya.
The hot clouds were growing by day, vulcanologists said.
A National Disaster Management Agency report said an estimated 20,491 people have been evacuated in shelters so far.
The government's alert status remained at its highest level, after violent eruptions in recent months from the volcano that lay dormant for four centuries.
The Center for Volcanology and Geological Hazard Mitigation put the volcano status on its highest status.