Strange cloud activity in Belgium has prompted claims of a UFO sighting, while some believe it to be a simple storm cloud rather than alien visitation.

In the video clip below, one can see a storm cloud formation, although thunder and lightning cannot be heard or seen.

But what's interesting about the video is the light within the cloud appears to continuously flicker off, before coming back on again in a steady flow. This definitely does not seem like normal lightning activity.

"Lighting does not last more than a split second, so there is some kind of powerful energy source inside to create this light," affirms UFO Sightings Daily creator Scott Waring.

And so far, the video has gone viral with nearly 30,000 views on YouTube, with many finding the phenomenon odd and believing it to be a UFO sighting hidden under the guise of a cloud.

However, others on YouTube fail to see this as anything out of the ordinary, much less a UFO sighting.

"There are no UFOs, just an idiot making us watch a video of a cloud," writes QuantumSanctum.

"How can there be a light so bright out of nowhere? And no thunder... I believe clouds and UFOs have a lot to do with each other," continues vcarreon04.

Keep in mind, however, that the uploader of this video is obviously a UFO enthusiast, looking for evidence to support UFO sightings around the world.

However, it doesn't take away the eerie footage of a thunder cloud constantly being lit, yet without any sounds to indicate a storm being active.

So what do you think? Do you think this video is proof of a UFO sighting or not?