An alleged floating alien city in in Yueyang, China shocked thousands of residents. The sighting has prompted several theories including claims that it was a portal to another dimension. UFO hunters believes it is a sign of extraterrestrial beings, meanwhile, some netizens debunked alien and otherworldly claims.

It is not the first time that a floating alien city was seen on China. Previously, a similar view was seen above water. An alien city was reportedly seen floating over Foshan in the Guangdong province of China in October 2016. UFO hunters believed these cities were created by aliens. Other conspiracy theorists dubbed it as Project Bluebeam, a fake hologram experiment concocted by the government to control citizens.

Famous UFO hunter Scott C. Waring said that the floating city is actually a UFO mothership. "I believe that this is a UFO mothership that is using the China smog problem for its own benefit so that it can make a rare appearance by flying low and doing some serious research on the humans in Yueyang city," Waring said according to Daily Express. He added that aliens seems very interested in China.

Others believes it is a gateway to a parallel dimension which appeared shortly as the portal opened. On the other hand, some are debunking the strange theories. According to Daily Star, weather experts and explained that the image was only an optical illusion -- a natural mirage called Fata Morgana.

The so-called Fata Morgana is a phenomena where distant objects such as boats appear to look like giant skyscrapers due to optical distortion as the rays of light bend while passing through air with different temperatures. A netizen also claimed that the floating alien city was merely buildings surrounded by thick fog. Scott Brando debunked paranormal claims showing photos of building similar to the alleged alien city.