A Bulgarian YouTuber has made headlines all over the world after filming a potential UFO, but the authenticity of the claim has been already challenged.

"The video shows an unusually bright light moving from horizon to horizon. This is exactly what you would expect from the International Space Station (ISS), which it just so happens was flying over the town where the video was captured at the exact time the video was captured,” Alejandro Rojas, editor at Open Minds UFO News and former spokesperson for the Mutual UFO Network, argues.

The video, posted by one "nedialko kostadinov," shows the unusual object passing behind numerous wires and structures and changing colors and intensity.

The video is called UFO NK 61, presumably because it is believed to be a UFO taken by a man with the initials NK, and is the 61st UFO video Kostadinov has taken.

Although upon further review, many of these videos also appear to be the ISS, others look like bright stars, but some are a bit more mysterious, Rojas says.

UFO NK 61 was taken in Haskovo, Bulgaria on August 4, 2013 at 5:13 am, according to Kostadinov.

This is precisely the time the ISS was overhead according to the satellite tracking website Heavens Above, Rojas points out.

Huffington Post was the first the break the story about the Bulgarian UFO, describing it as “changing colors and intensity.”

Near the beginning of the video is what appears to be an aircraft of some kind, possibly behind the UFO. And several commenters have already chimed in on the YouTube page, claiming to have also seen the same object within 24 hours of the posting of this video.

HuffPost showed the video to Ben Hansen, the lead investigator of the Syfy Channel's "Fact or Faked: Paranormal Files." Surprisingly, Hansen liked the video and did not think this particular UFO was a hoax.