The UK and other western countries have been urged by the World Health Organisation to ensure that they are ready to deal with a terrorist attack using biological weapons, such as anthrax, botulin or the smallpox virus. The problem is that such horrific weapons are relatively easy to make, and there is no feasible protection against a mass attack. Fears were further raised by the US seizure of all crop-dusting aircraft in the country; aircraft which could be used to spread biological or chemical agents. US agents are also frantically following up reports of possible terror suspects applying for licenses to transport hazardous materials by road.

The intentional use of viruses, bacteria, other microorganisms, or toxins derived from living organisms to cause death or disease in humans, animals, or plants (US Army Field Manual definition). See also biological warfare agent.

the use of bacteria or viruses or toxins to destroy men and animals or food

See biological operation