Sources: UK chemical attack foiled
LONDON, England (CNN) -- Counterterrorism police have foiled an apparent plot to launch a chemical attack in Britain, according to U.S. and British security sources.
The sources said the suspects had plans to lace a bomb with a chemical called osmium tetroxide.
The plot was to combine that chemical with explosives that could create a toxic cloud on detonation, the sources said.
Police suspect such a device could have been used to target a shopping center, an airport terminal, a nightclub, or a crowded city center.
There is no suggestion by police sources that any osmium tetroxide was found in possession of the suspects, or that they had managed to obtain any.
Tuesday afternoon, a spokesman at Scotland Yard said investigators were not prepared to discuss the alleged plot.
Chemical experts said osmium tetroxide is toxic, openly available, and used primarily in research laboratories. It can give off a vapor that would cause skin and eye irritation. In confined spaces it can be lethal.
This is the first time osmium tetroxide has been associated with an alleged terrorist plot.