There were no fatalities or injuries from the eruption on Sumatra Island, Indonesia’s Volcanology and Geological Hazard Mitigation Centre said.
Villagers are advised to stay at least three miles from the crater’s mouth and should be aware of the peril of lava, the agency said.
Some 30,000 people have been forced to leave their homes around the mountain in the past few years.
A thick layer of ash covered several villages up to 12 miles from the crater, according to Armen Putra, an official at the Mount Sinabung observation post.
The volcano, one of two currently erupting in Indonesia, was dormant for four centuries before exploding in 2010, killing two people.
Another eruption in 2014 killed 16 people, while seven died in a 2016 eruption.
Sinabung is among more than 120 active volcanoes in Indonesia, which is prone to seismic upheaval due to its location on the Pacific “Ring of Fire”, an arc of volcanoes and fault lines encircling the Pacific Basin.