The US military accidently shipped live anthrax samples to government and commercial laboratories between March 2014 and March 2015.

The flawed shipments occurred at a military post in a desolate stretch of the Utah desert that has been testing chemical weapons since it opened in 1942.

The samples ended up at 18 labs in nine states and an Army lab in South Korea. The states include California, Delaware, Maryland, New Jersey, New York, Tennessee, Texas, Virginia and Wisconsin. This led leading to more than two dozen people to get treatment for possible exposure.

DC spokesman, Jason McDonald said that although exact lab locations had not been identified, they are mostly private and some are operated by government and public institutions.

He said that four people at labs in Delaware, Texas and Wisconsin were recommended to get antibiotics as a precaution.

Military officials said that they were not aware of previous problems with anthrax. However, Dugway Proving Ground, which is 85 miles west of Salt Lake City, has previously had at least two other problems with chemical weapons.

An internal investigation was launched by the officials, but the results were not released. Questions regarding the incident were not answered. In 2011 Utah Gov. Gary Herbert said that he met with the commander and the issue had been resolved.

Gen. Ray Odierno, the Army chief of staff said that the problem may have been caused due to a failure in the technical process of killing, or inactivating, anthrax samples.

The Dugway Proving Ground was created by President Franklin D. Roosevelt. It has gone through name changes and been closed and reopened several times.

Dugway employs about 1,700 people, including a mix of military and nonmilitary scientists, chemists, microbiologists and engineers.