During the Korean War (1950–1953), multiple U.S. Air Force pilots reported encountering bright, fast-moving aerial objects while flying missions between Wonsan and Sunchon. The objects were described as silver or glowing spheres capable of sudden acceleration, sharp turns, and pacing military aircraft—outperforming known jets of the era. Radar contacts occasionally coincided with visual sightings, ruling out simple flak or reflections. The incident is considered one of the earliest combat-zone UFO encounters, predating modern drone or missile technology.