Creepy footage emerging from Kazakhstan shows a mysterious black and smoky ring hovering in the sky.
The mysterious sight disappeared into thin air after two minutes on camera above the small town of Shortandy, near the capital of Astana on Saturday morning.
Looming in the sky for at least 15 minutes, the strange circle has prompted commenters on YouTube to come up with hundreds of possible explanations, from bizarre weather patterns and explosions to UFOs and the beginning of the apocalypse.
"It was like a black cloud. We saw it at around 4 pm on April 3. It dissipated like smoke, but it was completely odorless," local resident Oleg Menshikov told Today.kz.
Some suspect the bizarre phenomenon to be caused by an "extra-terrestrial force", while other hypothesised it may be caused by thermal microbursts in the atmosphere, whatever that means.
YouTube commenter Neceros said "it's satan's butthole" while M AL suggested "its an illuminati sign sent by Rihanna".
An associate physics professor at the Northern Kazakhstan State University estimates the ring was at least 100 metres in diameter and was floating anywhere from 200 metres to one kilometre above the ground.
Professor Andrey Solodovnik said it was most likely the result of a combustion in the local area, although a similar occurrence in Leamington Spa last year still goes unexplained.
In April 2014 schoolgirl Georgina Heap captured footage of an almost identical black ring in the sky above Warwick Castle.
UFO expert Nick Pope described the video as "truly bizarre" and ruled out the idea of it being a smoke ring.
He added: "One other possibility is that the shape is made up of millions of bees or other insects, but I've never heard of insects behaving in this way before, so if this is the explanation, it's a real-life X-File."