Indonesia has nearly 130 active volcanoes, more than any other country, and while many show high levels of activity it can be weeks or even months before an eruption.
Raditya Jati, a spokesman for the agency, said in a statement that the eruption from the Mt. Ile Lewotolok volcano, about 2,600 kilometers east of Indonesia's capital of Jakarta, had caused panic among those living nearby.
About 2,780 people from 26 villages had sought refuge, although no casualties have so far been reported, Jati said.
Indonesia’s Volcanology and Geological Hazard Mitigation Centre said on its website that the area near the volcano is likely to be inundated with “hot clouds, lava stream, lava avalanche, and poisonous gas.”
Kasbani, the head of the center, told Reuters that the status of the volcano was raised to the second-highest level on Indonesia’s four-tier alert system due to “increasing threats.”