22 exposed to anthrax at US base in South Korea

22 people have been given emergency medical treatment at a US Air Force base in South Korea after they were exposed to a possible live sample of the deadly biotoxin anthrax.

The anthrax was destroyed on Wednesday when a sample initially expected to be inactive and destined for a training exercise was reveal to be potentially active - after it was sent by accident from a lab in Utah.

None of the people who came into contact with the sample showed signs of exposure, authorities said in a statement, but they were given "appropriate medical precautionary measures to include examinations, antibiotics and in some instances, vaccinations".