Agents foil British chemical bomb plot: BBC

Security officials in Britain said on Tuesday they uncovered a scheme to build a chemical bomb capable of creating a toxic cloud that would choke people to death.

The BBC reported that police and intelligence staff from both the United States and Britain intercepted messages between organizers of the plot involving the chemical catalyst osmium tetroxide.

           

OSMIUM TETROXIDE (OsO)

a chemical compound oxide of the element osmium formed when powdered osmium is exposed to air pungent smell; name derived from Greek word for 'stench' also called 'osmic acid' colourless crystals highly poisonous inhalation can lead to edema of lungs (fluid accumulation) or death used in electron microscopy

The plan apparently involved mixing the chemical into an explosive such as ammonium nitrate fertilizer, which was used in the attack in Oklahoma City in 1995 and bombing of a nightclub in Bali in 2002. This time, the idea was to detonate the device in an enclosed space where the vapour would not easily disperse. 

Security sources told the BBC there was no evidence the plotters had obtained any osmium tetroxide. The same sources said the ringleaders were sympathetic to the aims of al-Qaeda and were planning to target British civilians.

Nine Britons and one Canadian with alleged ties to Islamic militant groups were arrested last week and are being held on suspicion of planning a terrorist attack. Half a tonne of ammonium nitrate fertilizer was seized in the same set of raids.

• FROM APRIL 2, 2004: RCMP confirm link between London and Ottawa arrests

There is no word on whether those arrests are connected to the alleged osmium tetroxide plot.

British police said they "were not prepared to discuss" the BBC report.

Scientists use osmium tetroxide in electron microscopy. It can only be purchased from specialized suppliers.

The almost-colourless chemical gives off a foul stench. When dispersed as a vapour, it would attack the eyes, skin and lungs, with victims suffering asthma-like symptoms as they choke to death.