The Semeru volcano in Indonesia's East Java province erupted on Saturday, sending residents fleeing as a huge column of smoke blanketed nearby villages in darkness, an official said.
Mobile phone footage broadcast by local television showed villagers running and screaming in panic as a huge cloud of ash approached them.
"Allahu akbar (Allah is greater)!" residents were heard shouting.
Lumajang district chief Thoriqul Haq said the volcano had been active since late Friday.
"Now it's dark in villages," he told the Kompas TV news broadcaster. "We don't if it's cold or hot lava."
There were no immediate reports of casualties or damage, he said.
