Mount Sinabung in Tanah Karo, North Sumatra, erupted again on Thursday morning sending volcanic ash as high as 3,000 meters into the air.
Areas to the east, south and southeast of the volcano were blanketed with volcanic ash, head of the National Agency for Natural Disaster Control (BNPB) Sutopo Purwo Nugroho said.
"Black smoke was spurted out from the crater of the volcano from 6:00 a.m. to 8:50 a.m. local time," Sutopo said in a statement quoted by the Antara news agency on Thursday.
A series of small explosions were recorded on Wednesday afternoon and continued until Thursday morning, Sutopo said in Medan.
The Volcanology and Geology Disaster Mitigation Center (PVMBG) warned the local population and mountain climbers to stay at least 2 kilometers away from the crater, but no evacuation order had yet been issued.
The volcano erupted last September forcing thousands of people to leave their houses and stay in evacuation tents and public buildings.
A previous eruption of the volcano was recorded in August 2010.