[20] Al-Qaeda operatives in England were arrested discussing a plot involving a "poisonous invisible gas", probably cyanide. Terrorists operating in Germany, Britain, and Italy were arrested in a plan to use tomatoes to transport a "liquid that suffocates people". The apparent leader of the plan, a Libyan, was arrested and led the foiling of the attack. The target was believed to be an American government building in either Rome or London or both. The terrorists sought to use ten liters of cyanide to spill into the ventilation ducts.
[21] Convicted terrorist, Ahmed Ressam said during his trial that when he was in Al-Qaeda camps, the militants were taught how to pump gases including cyanide into an office building's ventilation system.
[22] The supplies of cyanide can come from many sources.
On August 22, 2002, it was reported that Argentinian police were searching for 20 tons of cyanide that was stolen from a truck near Buenos Aires. The vehicle was later found, but the container handling the cyanide was now handling other items in the truck. This occurred around the same time as the seizure of the Mexican truck with tons of cyanide. Although that truck and most of the cyanide was eventually recovered, a large portion of the substance was still missing- more than enough for one or more large terrorist attacks.