UFO: Mysterious black ring spotted floating in sky

A strange phenomenon was witnessed in Tucuman province in Argentina when residents heard a loud noise and noticed a massive black smoke ring slowly rising in the air.

Footage shows the odd circle hovering over Tucuman province in Argentina , moving slightly from side to side.

Some netizens were convinced it was a UFO, and others believed it was a freak weather pattern or fire.

Others believed it could have been a swarm of mozzies spinning in the sky.

Some residents compared the sight to a tornado.

It comes after mysterious flying lights were seen hovering above the city of Deyang, China.