The eruption of the Machimahuida volcano in southern Chile left thousands of people in darkness, as ash saturated the air, the dpa reported.
"There was no visibility whatsoever, it seemed like it was night- time," said Arturo Carvallo, the mayor of the town of Futaleufu.
Chilean President Michelle Bachelet called for residents to remain calm. In 1991, people in the same area, around the town of Chaiten, saw the Hudson volcano further to the south bury crops, woods and animals under tonnes of ash.
Through radio messages, the authorities called the inhabitants of rural areas to move to more urban areas. Hundreds of people in the region live in areas of native woodland that are very difficult to reach.