NASA cut a live stream from the International Space Station (ISS) when what some viewers say were three UFOs raced out of the Earth's atmosphere, causing a discussion on YouTube about the proof of alien life, The Mirror reported.

As the lights were seen blasting off the planet, the live video feed was cut by NASA with a display saying: "Please stand by. The High Definition Earth Viewing experiment is either switching cameras, or we are experiencing a temporary loss of signal with the International Space Station."

But for conspiracy theorists, the video "UFO Mysteries: UFOs, Angels Or Biological Creatures Seen Leaving The Earth?" is a proof that aliens exist. The video has been viewed nearly 500,000 times with more than 100 comments.

"BINGO Caught them red handed leaving earth's orbit," one viewer said. "That's the kind of proof that is needed."

Another also said that cutting the cameras "just confirms it's true."

Meanwhile, one viewer commented that there were no aliens, saying: "The flash of light you saw in the sky was not a UFO. Swamp gas from a weather balloon was trapped in a thermal pocket and reflected the light from Venus."

Aside from this video, there are other viral videos from the live streams from the International Space Station that apear to capture extraterrestrial activity. In January, UFO hunter Toby Lundh spotted what he said was an UFO just outside the space station as he was monitoring the live feed on his laptop, the International Business Times reported.

However, there is a possiblity that the YouTube video has been doctored, or the unexplained objects are simply a trick of the light, reported Sunday Express.

NASA has not provided any explanation about the flashing lights captured during its live broadcast.