Two of nature’s most spectacular forces produced an incredible brew in the skies of Chile as a volcanic eruption met a lightning storm.

Tonnes of dust and ash from the eruption of the Chaitén volcano poured into the night sky just as an electric storm passed overhead.

The resulting collision created a spectacular sight as lightning flickered around the dust cloud amid the orange glow of the volcano.

The eruption was all the more spectacular because the Chaitén volcano, 800 miles (1,290km) south of Santiago, has been dormant for hundreds — if not thousands — of years. The Patagonian volcano began erupting on Friday and the 12-mile-high plume has left vast tracts of land coated with a layer of ash.

Authorities in Chile were worried by the violence of the eruption yesterday when lava spewed out with increased ferocity.

“The situation has changed suddenly,” Rodrigo Rojas, a national emergency official, said. “Today the volcano is erupting with pyroplastic material on a different scale.”

Authorities ordered the evacuation of the remaining 300 people from the area. More than 4,000 people had already been evacuated from the town of Chaitén, which is six miles from the volcano. Luis Lara, a government geologist, said “The entire volcano will not collapse, but the eruptive column could, and that is sufficient material to be displaced into areas nearby. Lava flow would not reach Chaitén, but hot fragments, ash and gas could.”

Authorities are evacuating a second town, Futaleufú, which has been coated with ash. Many of Futaleufú’s 1,000 or so residents had crossed into Argentina, where some areas have also been showered with ash.

Last week Argentine authorities closed schools and treated a number of people for breathing problems.

In the worst-affected areas, ash is more than 15cm thick in places, coating houses, vehicles and trees, and contaminating water supplies.

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