The US Armed Forces accidentally sent live samples of anthrax to laboratories in nine US states and one to its military base in South Korea, the Pentagon said on Thursday.
The sample sent to Osan air base in South Korea was destroyed immediately after it was revealed that it was not inactive anthrax as believed but in fact live bacteria, Efe news agency cited the US Forces Korea (USFK) as saying in a statement.
"There is no known risk to the general public, and there are no suspected or confirmed cases of anthrax infection in potentially exposed lab workers," both USFK and the Pentagon claimed.
USFK added that some troops could have come into contact with the substance on May 22 during a training exercise, but so far none of them have shown any anthrax-related symptoms.
Anthrax samples were also sent to laboratories in the US states of Maryland, Texas, Wisconsin, Delaware, New Jersey, Tennessee, New York, California and Virginia between March 2014 and March 2015.
All the samples were sent from a military laboratory in Utah, as part of a programme to test for the identification of biological threats.
Pentagon spokesperson Steve Warren said an investigation into the incident was underway and that the Department of Defense has halted anthrax shipments until the matter was cleared up.