Strange hum in Sweden
© YouTube/Rene Krupinski
YouTuber Rene Krupinski shared the bizarre clip which features a low unusual fluctuating noise appearing to emanate from the sky in Sweden.

The two minute and 21 second video was reshared by another YouTube channel today.

Comment: The footage was originally published in January, 2018.

It is the latest in a string of unusual noises to heard from the sky worldwide - with unusual hums and horrific "trumpet" noises.

Scientists have been theorising what is causing this noise, with theories ranging from shifting ice to distant storms.

Krupinski shared the video of him standing in a snowy landscape, which is silent apart from a constant low buzz - and a passing snowmobile.

Footage begins with him filming the evening sky as the odd sound radiates across the landscape.

It is briefly interrupted when a snowmobile passes, but once it has gone the pulsing hum remains.

He was standing in any almost empty snow-covered landscape, with no obvious source of the ambient noise.

Krupinski described the chilling sound as coming from "the whole sky" and said usually the area is "very quiet".

In his post, which was reshared today by channel Atlantic Paradise Universe, he said: "Something strange it going on.

"I heard this sound, it was constant, as if the sound gave vibrations in the air."

He added: "I have never heard it before. It is usually a very quiet place here. I am sure the sound came from the sky or atmosphere.

"The sound came from the whole sky. I could not locate if it came from north, south, east of west, it filled it all. It was strange."