What would be your first thought if a black smoke ring appeared and hovered in the skies above Sentosa?

Furthermore, instead of dissipating after a few seconds, like what you might expect, the large smoke ring continued drifting over the beach, above the heads of beachgoers.

Nope, your eyes are not deceiving you.

This bizarre sight was caught in a TikTok shared by user "danenrdnslm5" on Aug 7.

@danenrdnslm5 errmmm, should we start running? #trending #sentosa #singapore ♬ original sound - Manic Hispanic

The clip, which is captioned, “errmmm, should we start running?”, has garnered more than 29,000 views as of Aug. 8.

Creepy.

"Nope"?

Could it be a swarm of bees?

Nuruddin Selamat, who shared the video, told The Straits Times that he and his friends were having a picnic at Tanjong Beach in Sentosa when they spotted the smoke ring.

Thinking it might be a swarm of bees, Nuruddin considered if he should run, but decided to record the evidence first otherwise "no one would believe me".

Other curious beachgoers followed the ring as it drifted away, he added.

The ring faded away and disappeared after a few minutes.

Sentosa's previous black rings

This was not the first time black rings have been seen over Sentosa.

On Jan. 5, a video shared in the "Singapore Incidents" Facebook group showed a similar black ring hovering in the air above the island.

It was taken from HarbourFront jetty, opposite Sentosa.

An earlier video circulated in 2017 on Sgag's Facebook page also depicted the uncanny phenomenon.

In the comments, online users chimed in heartily on what could have caused the sight, and these were some of the popular theories:

• Alien spaceships experiencing problems with their camouflage system
• Birds or insects
• Vaping
• A dirty camera lens

One of the more rational suggestions came from a user who said the ring was likely emitted from a ship's smokestack or funnel just offshore, and carried in by the wind.

Fireworks testing from Wings of Time could have caused it

Another plausible theory is that the smoke ring was from fireworks testing from one of Sentosa's many shows, with Wings of Time deemed as the likely culprit.

Wings of Time is a light show that includes laser, fire and water effects, as well as a fireworks display.

It is located at the nearby Siloso Beach in Sentosa, and operates daily in the evenings.

But could fireworks testing really create such a persistent smoke ring that hangs in the air?

Well, yes.

Here's an example of smoke rings being created as part of a pyrotechnics display at the Burning Man community art event in 2008:

Documentaries have also debunked the theory that these rings are of extraterrestrial origin or due to an anomaly in the weather.

Instead, they are most likely vortex rings caused by a plume of hot air that is shot up into the atmosphere.

As the plume passes through the cold air, smoke could also wrap around it, creating a circular smoke ring.

These smoke rings have also been spotted in many other parts of the world, such as in Detroit in 2020, and Moscow in 2018.

They can reportedly be created by volcanic eruptions, chemical reactions from factories and fireworks displays.

Mothership has also reached out to Sentosa for comment.

Top image from danenrdnslm5 on TikTok.