The area near Mount Sinabung was on high alert, and the disaster mitigation agency asked people to avoid activities within a 3-mile radius of the volcano after it erupted several times Monday and Tuesday, the Antara news agency reported.
Mount Sinabung has erupted seven times since Monday, sending smoke and ash into the air and lava flowing down its sides, the National Disaster Mitigation Agency said.
People living to the southeast of Mount Sinabung have been asked to evacuate because of the lava stream and hot clouds.
Mount Sinabung, on Indonesia's Sumatra island, has forced 19,126 people from their homes since sporadic eruptions began in September.
In late November, as the volcano's lava dome swelled and it kept spitting out ash, experts placed it under the nation's highest alert status, the Wall Street Journal reported.
Mount Sinabung released several lava flows Monday and Tuesday as its dome began to collapse, the National Agency for Disaster Management said.
"I think it's almost at the end of its activity," Surono, of the Indonesian Center for Volcanology and Geological Hazard Mitigation and one of the country's leading volcano experts, told the Wall Street Journal. "The lava dome began forming in early November, and now it's collapsed many times."