An Indonesian volcano spewed ash thousands of metres into the air on Friday in its most violent eruption since rumbling back to life earlier this week for the first time in 400 years.
Thousands of people have fled their homes since the 2,460-metre (8,100-foot) Sinabung in northern Sumatra started to erupt on Sunday after centuries of inactivity.
"The volcano erupted at 04:38 am which has lasted for 13 minutes and sending a column of ash as high as 3,000 metres (10,000 feet) into the air. This is the biggest eruption," government volcanologist Agus Budianto told AFP.
"We recorded continuous tremors since 7:00 pm Thursday that indicated an intense magma movement inside the volcano," he said.
Police had evacuated people from the danger zone in a six-kilometre (four-mile) radius from the volcano peak.
"We're afraid that some locals had returned back to their village from emergency shelters," he said.
Budianto said the eruption was felt about eight kilometres (five miles) away.
Indonesia sits on the Pacific "Ring of Fire", where the meeting of continental plates causes high volcanic and seismic activity. It has more active volcanoes than any other country.