FBI: Terrorists Trying 'Improvised' WMDs

April 2 -- Terrorists in the United States could be trying to concoct biological or chemical agents to use as "improvised weapons of mass destruction" in attacks on Americans, the FBI warned in an intelligence briefing sent to law enforcers.

In the bulletin, revealed to ABCNEWS by law enforcement sources, the bureau points to the apparent attempts by terrorists to produce the deadly poison ricin in London and Paris as an indicator that extremists want very much to unleash chemical weapons.

"Recent events, including the January 2003 arrests in the United Kingdom of Algerian extremists apparently attempting to produce ricin toxin in their residences, indicate an ongoing interest among terrorists in developing improvised weapons of mass destruction," the bulletin said.

"In addition to attempts by international terrorists to develop chemical and biological agent production capabilities in residential settings, numerous examples in the United States of individuals and groups who have successfully developed crude chemical and biological agents underscore the potential threat posed by these types of weapons."

The bulletin, which is developed from counterterrorism investigations and analysis, also refers to five cases between 1984 and 1997 in which individuals or groups either used, produced or tried to produce biological or chemical agents to use as weapons.

The concern is heightened because of the availability of information about the production of such agents, and the ease with which many of the materials needed for the production of the agents can be acquired.

"Using commercially available materials, clandestine laboratories with varying levels of sophistication — from basic household equipment to more complex fermentation systems — could produce a number of chemical and biological agents, including cyanide compounds, C. botulinum (causative agent of Botulism), ricin toxin, and Salmonella," the bulletin said.

Among the cases cited by the FBI were the use of Salmonella bacteria to contaminate salad bars in Oregon in 1984 by followers of the Bagwan Shree Rajneesh in which 751 people fell ill; the production in 1995 of ricin by members of an anti-government extremist group who planned to use it against a deputy U.S. marshal; and the arrest in 1997 of a psychologically disturbed New Jersey man who was developing a viable process to produce a sarin-like nerve agent.