Subscribe | UPI Odd Newsletter Subscribe CHONGQING, China, July 17 (UPI) -- Two recent UFO sightings have caused a stir in eastern China, with "twinkling lights" causing an airport to shut down temporarily. The lights were observed above the terminal at Hangzhou's Xiaoshan Airport on the evening of July 7, causing 18 flights to be delayed or redirected, China's official Xinhua news agency reported, adding that the lights may have come from a private aircraft. A source told China Daily the lights could have been caused by a military operation. Advertisement On Thursday, a second UFO was seen above Chongqing, with one witness saying four "lantern-like objects forming a diamond shape" floated above a park for about an hour, Shanghai Daily reported. "I stared at it and it did not move," another witness said. "After hovering for an hour, the thing started to fly higher and finally out of people's sight." Officials are trying to determine if the unidentified objects were private or military craft, rocket flares, reflections, or something else altogether.