PYONGYANG, NORTH KOREA — Reports from South Korea have raised fears that Kim Jong Un's government may be putting viruses on their ICBMs.

CNN reports that one of at least four soldiers who defected from North Korea was found with anthrax antibodies in his system, suggesting he was either vaccinated, or exposed to the virus at some point.

The North has also reportedly begun testing loading anthrax into intercontinental ballistic missiles, to determine whether the bacteria can withstand the high temperatures of atmospheric reentry.

Anthrax is caused by exposure to Bacillus anthracis spores. It causes flu-like symptoms, and can kill 80% of those exposed within 24 hours, unless antibiotics are administered.

South Korea's Centers for Disease Control and Prevention bought 1,000 doses of anthrax vaccine for agents or civilians. The Blue House — South Korea's executive office — has an additional 350, ordered by the previous government.

Fears of a biochemical attack come just weeks before the South is set to host the 2018 Winter Olympics.