"On April 13, 2004, Jordanian security forces foiled an al-Qaeda plot against the nations intelligence agency. The plot, reported on April 26 by Agence France-Presse (AFP), involved a plan to use trucks packed with 20 tons of chemical explosives, including blistering agents, nerve gas and choking agents. Jordanian officials estimated that had the attack been successful, the amount of chemicals involved had the potential of killing up to 80,000 people."
Got a link?
This is a pretty thorough link: http://news.scotsman.com/index.cfm?id=482512004