A circle of blinking lights hovering in the cloudy night sky above Houston, in the US state of Texas, has sparked UFO panic as dozens of photos of videos of the strange event continue to circulate on social media.

Sceptics are not convinced, though.

The event was recorded on August 11 during a thunderstorm, prompting some to speculate that bad weather may have had something to do with what people saw.

Others noted that the sightings happened less than 20km from the Johnson Space Center, suggesting the lights could have been NASA testing an experimental aircraft.

Carolyn Summers, vice president for astronomy at the Houston Museum of Natural Science, told KPRC-TV : "I think the trick in UFO's is figuring out what else they could be. It's easy to say that could be the aliens.

"The more people who see it in different directions, the more likely we are to figure out where it is, what it is and see if we can explain it."

Huffington Post polled its audience on what they think the UFO is and 30 percent of respondents answered "aliens".

A mass UFO sighting in Houston, Texas, has sparked panic. (Twitter) (Twitter)