A photo posted by Kyle Mijlof (@mijlof) on Nov 8, 2015 at 12:28pm PST Subscribe | UPI Odd Newsletter Subscribe CAPE TOWN, South Africa, Nov. 9 (UPI) -- Meteorologists said the mysterious "UFO Clouds" photographed by social media users in Cape Town, South Africa, are a phenomenon called lenticular clouds. Pictures of the "UFO Clouds" went viral during the weekend as Cape Town residents posted their photos to Instagram with questions about the origins of the strange formations. Advertisement "Did you notice the UFO's flying over #capetown yesterday?" Instagram user instagram_sa wrote. Meteorologists said the formations in the photos are known as lenticular clouds, which result from strong wins carrying moisture over mountains and other uneven surfaces. The air sometimes cools over the large features, leading to the disc-shaped cloud formations. A photo posted by Joshua Oates (@joshua.oates) on Nov 8, 2015 at 11:27pm PST Advertisement Read More Boston transit police: No rabbits on subway seats, please Penguin forms years-long bond with Brazilian rescuer National Hot Dog and Sausage Council: Hot dogs are not sandwiches