This is becoming quite regular, sightings of UFOs over Chinese airports that cause flights to be re-directed. An UFO was seen hovering in the flight paths of aircraft in Chinese airspace.
Chinese officials once more shut down airspace over the airport and didn't allow incoming aircraft to land, other craft apparently were allowed to take off.
The story takes a while to get to in this news report, however notice the preceding stories where pictures of Chinese lanterns appear, somewhat larger than I have seen here in England. These lanterns would travel much higher and further than normal lanterns, giving the impression of UFOs. I don't suggest that this UFO over the airport is one of these, rather this is what the Koreans saw in the other story line here.