Mount Sinabung in Sumatra has erupted again, discharging volcanic ash to a height of 7km.
Sinabung had been inactive for four centuries before erupting in August 2010 and again in September.
Observation post official Hendra Gunawan said there have been more than 40 eruptions since an alert was issued on 3 November.
"(On Thursday) the eruption occurred that lasted for 17 minutes, and there was 7000 metres high of volcanic ash,'' he said.
The Indonesian Centre for Vulcanology and Geological Hazard Mitigation has put the volcano's status on alert level three.
The ABC reports Sinabung is one of almost 130 active volcanoes in Indonesia.
Around 5500 people are staying in evacuation centres.