Indonesia's Marapi volcano erupted on Sunday, with ash rising 1,300 metres (4,300 feet) from the peak six weeks month after a fatal eruption, according to the country's geological agency.
The volcano in West Sumatra province erupted at least twice by 0337 GMT on Sunday, the agency said, urging the evacuation of people within 4.5 km (2.8 miles) of the centre of the eruption, with the possibility of lava flows in rivers and valleys.
"In case there's a rain of ash, we urge residents to also use masks in order to prevent respiratory illness," the agency said.
In December more than 20 people were killed after Marapi, one of Sumatra's most active volcanoes, erupted and spewed grey clouds of ash as high as 3 km (2 miles).
Indonesia straddles the "Pacific Ring of Fire", an area of high seismic activity atop multiple tectonic plates.
Volcanic ash from Sunday's eruption covered nearby houses, vehicles and evacuation tents set up by the local disaster agency, Reuters footage showed.
A number of residents went to health facilities for respiratory checkups, and the authorities distributed masks.
