London, Jan 19: Scotland Yard has launched a hunt for three Islamic terrorist groups following reports that they were planning a strike on Britain with biological weapons as police detained three men at one of the busiest airports of the country under anti-terrorism legislation. The disclosures came as police announced they had detained three men at one of Britain's busiest airports, arresting them under anti-terrorism legislation.

Immigration officials at Gatwick Airport held the men, aged 28, 29 and 30, on Thursday while they were "in transit" They are being held under the terrorism act 2000 at an unnamed police station in Central London. Police refused to disclose any further details.

Last week a 27-year old Algerian appeared in court charged with the murder of a police special branch officer in Manchester.

Detective constable Stephen Oake, 40, was stabbed during a raid on a flat in the Crumpsall area of the city last Tuesday. Four men have been arrested in Manchester in connection with the incident. The Manchester operation was part of the nationwide search for Ricin, one of the most poisonous substances known.

Bureau Report