Sky turns red as volcano erupts after 50 years

Ash and pumice has been shot six miles into the sky and plumed several miles wide above Chile's Puyehue-Cordon-Caulle volcano range, dropping a grey blanket over a huge area.

Winds have fanned the ash toward neighbouring Argentina, darkening the sky in the ski resort city of San Carlos de Bariloche, where the airport has been closed.

Authorities in southern Chile and Argentina are continuing to monitor the direction of winds after the eruptions.

More than 3,500 people stayed away from their homes in the area, which saw an eerie show of lightning dancing through the clouds of ash overnight.

Most of the residents in 22 settlements near the Puyehue-Cordon-Caulle volcanic complex have been evacuated since the eruption began on Saturday and have been staying in government shelters or friends' homes.

Rodrigo Ubilla, Chile's undersecretary of labour, said some people near the volcano had decided not to leave their homes because they did not want to abandon their animals.

In Bariloche, which is about 60 miles from the volcanic chain and coated in ash, authorities told residents to wear masks, stay inside and avoid driving because of poor visibility.

"We're in a state of alert here, we're not going outside," said local resident Marcelo Ambrosi.

"We saw everything was covered in white, and that it was not snow," he added. "It's a bit uncomfortable breathing-wise, like you're breathing in smoke."

Santiago Rozas, mayor of Lago Ranco, a town about 40 miles north of the eruption, said: "The situation is very complicated.

"The shift means that we will have a rain of ash, with damage for the population and a threat to smallholder farming."

Officials closed the border crossing at Cardenal Samore because falling ash lowered visibility on the mountain road.

The eruption is nearly 620 miles south of Chile's capital, Santiago. Authorities put the area on alert on Saturday morning after several earthquakes, and the eruption began in the afternoon. The National Emergency Office recorded an average of 240 tremors an hour for the first 12 hours, but that dropped to about 17 an hour by Sunday, interior minister Rodrigo Hinzpeter said.

With the Andes running along its entire length, Chile has more than 3,000 volcanoes, of which about 500 are considered active. 60 have erupted in the past 450 years.