In 1995 the US listed 17 countries which it said had biological weapons programmes. These were: Iran, Iraq, Libya, Syria, North Korea, Taiwan, Israel, Egypt, Vietnam, Laos, Cuba, Bulgaria, India, South Korea, South Africa, China and Russia. But Russian leaders insisted they had terminated their biological weapons programme years before.

Other countries including the USA and the UK have had biological weapons programmes in the past but these were ended in 1972 when international concern led to a treaty banning the production and stockpiling of these weapons.

During World War II Britain tested the use of anthrax as a weapon on the Scottish Island of Gruinard. The island was not decontaminated until 1987.

The Aum Shinrikyo group, which released Sarin on the Tokyo underground in 1995, also released anthrax. No one was infected.

The biggest human exposure to inhalation anthrax occurred in 1979 at a military biology centre in Sverdlovsk, Russia. Anthrax spores were accidentally released resulting in 79 anthrax cases, 68 of which were fatal.