Operation Crevice was the codename given to the largest counter-terrorism operation ever conducted in the United Kingdom. It involved the Metropolitan Police Service, MI5, MI6, the CIA, the ISI and Canadian intelligence services.  It is sometimes referred to as the fertiliser plot or the the fertiliser bomb plot. The plot - alleged to be an Al-Qaeda operation that was reportedly ordered by 'senior al-Qaeda figures in Pakistan and Afghanistan,'  aimed to target a series of sites in the United Kingdom with ammonium nitrate bombs. The ringleader and commander of the plot was Omar Khyam.
Links to July 7 Bombers
- Operation Crevice: MPS Statement by Deputy Assistant Commissioner Peter Clarke, Metropolitan Police Service, 30 April 2007, accessed 30.08.10
- Five get life over UK bomb plot, BBC News, 30 April 2007, accessed 30.08.10