The image released by US Department of Defense shows Bacillus anthrax vegetative cells and spores. (AFP)
Live anthrax samples were shipped to three laboratories in Canada by a US military lab, USA Today reported on Monday, following disclosures last week that samples of the bacteria were mistakenly sent to 11 US states and two other countries.
The newspaper cited two Defense Department officials as saying the samples sent to Canada came from the Dugway Proving Ground in Utah, where the other samples appear to trace back to as well. It is one of the U.S. military labs responsible for inactivation and shipping of biological material.
The Pentagon had no immediate comment on the report.
The US military said on Friday a total of 11 states had received "suspect samples," as did Australia and a US air base in South Korea. It ordered a sweeping review of practices meant to inactivate the potentially deadly bacteria.
It advised all laboratories for now to stop working with any "inactive" samples sent from the Defense Department.
To date, the United States has acknowledged that four US civilians have begun taking preventive measures that usually include the anthrax vaccine, antibiotics or both.
Twenty-two people at the base in South Korea were also given precautionary medical measures, although none had shown signs of exposure.
© Thomson Reuters 2015