US Military Base in South Korea Hit by White Phosphorus Leak; Residents Evacuated

South Korean authorities ordered a brief emergency evacuation of residents around the US Osan Air Base on Tuesday (28/07/2026). The precautionary measure was taken following the discovery of a leak of the hazardous substance white phosphorus at the military facility located south of Seoul.

Quoting a Reuters report on Tuesday (28/7/2026), the South Korean Ministry of the Interior and Safety confirmed that no casualties had been reported in the incident.

The Yonhap news agency reported that the evacuation order for local residents was lifted after about half an hour as decontamination proceeded, carried out by South Korean fire officials and US forces.

Osan Air Base authorities confirmed that emergency response procedures were executed immediately once the accident was detected. The base promptly established a sterile cordon to minimise the risk to military personnel and civilians in the vicinity.

“At 17.08 (08.08 GMT), due to a ground accident and as an extra precaution, Osan Air Base established a 1,000-foot (approximately 304-metre) safety perimeter to protect the base and local residents. Our emergency response professionals are currently managing an isolated situation within the installation, and we are handling this matter with great care and speed,” the official statement from Osan Air Base read.

A spokesperson for the US air base said the incident was triggered by an accident involving military munitions. The spokesperson added that technical teams were continuing to carry out assessments and in-depth evaluations to determine the exact cause and impact of the leak.

White phosphorus is a highly toxic chemical that can ignite spontaneously upon exposure to direct contact with air. In military use, the hazardous substance is commonly employed to create smoke screens on the battlefield and as munitions for incendiary weapons.