Thousands of people have been evacuated in the province North Sumatra after Indonesia raised its alert concerning Sinabung volcano to the highest level on Thursday.
Indonesian authorities say there has been a "sharp rise" in volcanic activity in the last two days and they expect it to erupt within days.
National disaster management agency spokesman Sutopo Purwo Nugroho said the volume of the volcano's lava dome is to expand as clouds of smoke and rock spewing from the volcano have travelled up to 7 kilometers away.
Soldiers and police have evacuated nearly 3,000 people from villages within the danger zone to a safe location.
Sinabung volcano first erupted again in 2010 after 400 years of silence and has erupted several more times since 2013. When it erupted in 2014, 16 people died. Thousands of people fled their homes during this activity and some still live in shelters.
"Volcanic activity is still high, triggering tremors," district military commander Lieutenant-Colonel Asep Sukarna told AFP.
Indonesia has 129 active volcanoes and sits in the Pacific’s "Ring of Fire," where tectonic plates collide and cause frequent seismic and volcanic activity.