White phosphorus leak at US Osan Air Base in South Korea prompts brief evacuation

Published Jul 28, 02:54 PM UTC

On July 28, 2026, a leak of white phosphorus occurred at the U.S. Osan Air Base in South Korea, prompting South Korean authorities to order brief neighborhood evacuations. The leak, described as a munitions-related accident, happened at 5:08 PM local time. U.S. forces established a 1,000-foot safety cordon and conducted decontamination with South Korean fire authorities. No casualties were reported, and the evacuation notice was lifted after about 30 minutes. White phosphorus is a highly toxic substance that ignites on contact with air and is used in smoke screens and incendiary weapons. The base spokesperson confirmed the accident and said the situation was being assessed.