One person has died and 41 suffered burns after a volcano erupted on Indonesia's Java island, officials said on Saturday.
Residents were filmed fleeing a giant ash cloud from Mt Semeru.
Witnesses described nearby villages covered in debris, and thick smoke blotting out the sun, leaving them in pitch darkness.
Airlines have been warned of an ash cloud rising up to 15,000m (50,000 ft).
The eruption took place at about 14:30 local time (07:30 GMT). Local authorities have set up a restricted zone within 5km (3 miles) from the crater.
Thoriqul Haq, a local official, told Reuters that a road and bridge from the area to the nearby city of Malang had been severed.
"This has been a very pressing, rapid condition since it erupted," he said.
The Volcanic Ash Advisory Center (VAAC) in Darwin, Australia said the ash appeared to have detached from the summit and was drifting south-west over the Indian Ocean.
The VAAC provides advice to the aviation industry about the location and movement of potentially hazardous volcanic ash.