A major volcano eruption turned day to dark night in eastern Russia as an ash cloud spread for hundreds of miles.
Videos show the doomsday scene after an outpouring from Shiveluch volcano in the Kamchatka region which turned the snow black.
Ash rose 12 miles into the sky, said reports, with a red warning to aviation from the plume, the highest category.
An area of 41,700 square miles was blanketed in darkness, an area larger than Scotland and Wales combined.
"The ash cloud extends 500 kilometres northwest of Shiveluch and is still growing," said Alexey Ozerov, director of the Institute of Volcanology and Seismology, of the Russian Academy of Sciences.
The volcano is known to be active but this was the largest ash cloud in at least 60 years in village Klyuchi close to the eruption, said locals.
The region was also hit by a 4.5 magnitude earthquake with an epicentre in the waters of Avacha Bay.
Residents said the morning sky had turned to darkness.
"The sun should be shining but is nowhere to be seen,” said one.
“The village is under a cloud of ash from the Shiveluch volcano…..
“It’s pitch dark…You cannot see anything.”
Commentary on another video said as day turned to night: “That's it, the lights are out.
“No sunlight.”
There was a threat that streams of hot lava could block roads, said officials.
Schools were closed .
"The ash reached 20 kilometres high [12 miles], the ash cloud moved westwards and there was a very strong fall of ash on nearby villages," said Danila Chebrov, director of the Kamchatka branch of the Geophysical Survey.
"The volcano was preparing for this for at least a year.”
The last major eruption was in 2007.
The consequences of the eruption of volcano Shiveluch may be more serious than that of Eyjafjallajökull in Iceland in 2010, climatologist Alexei Kokorin told RIA Novosti state news agency.
The Icelandic eruption closed airports around the world, with the biggest disruption to aviation since the Second World War.
Earlier this year, a mountain branded a "doomsday" volcano in Indonesia looked about to blow as hot smoke blanketed the local area.
Indonesia's Mount Merapi erupted with avalanches of searing gas clouds and lava, forcing authorities to halt tourism and mining activities on the slopes of the country's most active volcano.
Merapi, on the densely populated island of Java, unleashed clouds of hot ash and a mixture of rock, lava and gas that traveled up to 4.3 miles down its slopes.
A column of hot clouds rose 328ft into the air, said the National Disaster Management Agency's spokesperson Abdul Muhari.
The eruption throughout the day blocked out the sun and blanketed several villages with falling ash. No casualties have been reported.
