A volcano on the Indonesian island of Sumatra erupted for the first time in 400 years on Sunday, spewing a vast cloud of smoke and ash into the air and sending thousands of people fleeing from their homes.
Indonesia issued a red alert after the Sinabung volcano erupted, blanketing the area in thick and acrid black smoke, disaster officials said, although no casualties have yet been reported.
"It's clearly dangerous so we've raised the warning to the highest level, or red level," said Surono, head of the nation's volcano disaster alert centre.
"From the crater, it shot smoke and volcanic ash 1,500 metres (5,000 feet) into the sky," he said.
He said, "Initially we thought the ash and smoke were triggered by rain but now we know the driving pressure was from magma."
The 2,460-metre (8,100 feet) Sinabung in northern Sumatra has not erupted for more than 400 years but had shown "some volcanic activity" since Friday, Surono said.
"Our team is coordinating with district and provincial officials to monitor the situation," he added.
About 9,300 people have been evacuated from several affected villages to towns outside a six-kilometre "danger zone", search and rescue team official Mohammad Agus Wibisono said.
"The ash has spread to a distance of 30 kilometres (20 miles) from the volcano. Many of the villagers evacuated were farmers and they said the ash had settled on their vegetable farms," he said.
Disaster Management Agency spokesman Priyadi Kardono said that many residents in four affected villages at the foot of the volcano had fled their homes immediately after the eruption.