As suggested by the name, bioterrorism is the deliberate release of biological agents such as viruses, bacteria or toxins to cause illness or death.
Animals and crops are considered likely targets of bioterrorist activity, with livestock diseases deployed to damage the economy and cause public concern.
The Centre for Disease Control categorises the following as Category A agents, posing a risk to national security:
The single largest recent incident of biological terrorism was the 1984 Rajneeshee bioterror attack in Oregon, USA. Followers of Indian mystic Osho intentionally infected restaurants with salmonella, as part of a plan to incapacitate the electorate and win local elections. 751 people were infected, but there were no fatalities.