The Semeru volcano erupted again on the Indonesian island of Java on Saturday.
Local TV stations showed videos of people screaming and fleeing from a thick cloud of smoke that darkened the surrounding villages.
There were initially no reports of deaths or injuries.
The almost 3,700 meter high volcano is the highest mountain on Java and is located in the Bromo-Tengger-Semeru National Park in the east of Indonesia's most populous island.
He is always active.
Lumajang district chief Thoriqul Haq said a rumble had been heard from the volcano since Friday.
"Now it's dark in the villages," he told Kompas TV.
Indonesia lies on the so-called ring of fire in the Pacific.
The island state with around 275 million inhabitants has almost 128 active volcanoes.