Russian officials appear baffled over a massive cloud that turned day into night scaring pensioners over an area larger than Britain.
There are claims that the sudden darkness could have been caused by dust from a meteorite strike or a secret Kremlin weapon test.
Other explanations for mystified locals are a UFO, an unreported eclipse, the ‘work of the devil’, or smoke from raging wildfires.
Moscow’s defence and meteorological officials have has failed to comment on the cloud of darkness that hit three vast mainly Arctic districts in Yakutia region in the middle of the day.
There were no reports of meteorites, eclipses or weapons tests — let alone sightings of alien spacecrafts.
A local resident in from Eveno-Bytantaisky said:
‘Messages are going around about about a light flash registered by the US satellites, followed by increase of radioactive level and unusual activity of the military.
‘We are never going to be told is this was true or false.’
Some claimed it could be a ‘new type of weapon’ being tested by the Russian military.
Another source said: ‘This can only be explained by a UFO.’
Residents reported darkness beginning around 11.30am and lasting almost three hours on Friday.
Gloom descended on Eveno-Bytantaisky, Zhigansky and Verkhoyansky but none of these districts have been hit by wildfires that are raging in other Siberian localities.
The areas are so far north that at this time of year they have virtually 24-hour light.
But as one local said: ‘Day suddenly turned into a dark night’.
Another added: ‘I couldn’t see a thing without switching lights on.
‘We took torches to walk outside, but actually no-one wanted to be on the street because the feeling was as if something heavy in the air was pressing on your chest.’
Accounts spoke of a thick layer of dust after the darkness but this has been denied by some officials, who also expressed doubts that pollution from wildfires was the cause.
A local official in Nizhne-Bytantaisky settlement said: ‘At first it looked like it was a strong thunderstorm coming.
‘The air went dark, and got darker and darker, but this time unlike anything else we have seen before the darkness had a rich yellow undertone.
‘It was very unusual. We doubt the solar eclipse version.’
Konstantin Starostin, head of the settlement, said: ‘When the sun vanished, people started calling us, especially elderly people who were scared.
‘People who live here for many years said they had never witnessed anything like this.’
The sun was reportedly missing between the hours of 11.30am and 2pm.
‘We don’t know what to think. If this was linked to some kind of military tests, I would say so.’
There had been no advance eclipse warning, he said.
‘It could have been a meteorite, but surely not that big? This is really unclear.’
Almost all Arctic districts reported a significant temperature fall around the time of the daytime darkness.