British police today seized half a ton of ammonium nitrate fertiliser in a major anti-terrorist operation.
Eight men were arrested in the operation, in which police carried out 24 raids across London and the UK's "Home Counties".
Scotland Yard deputy assistant commissioner Peter Clarke , the UK National Co-ordinator for Terrorism, said: “There is no risk to the public.”
The ammonium nitrate – which can be used to make explosives – was found at an address in Boston Road, Hanwell, west London, he said.
Mr Clarke said eight men have been arrested.
Two were arrested in Uxbridge, one in Ilford, one in Horley, one in Slough and three in Crawley.
All were now being interviewed by anti-terrorist detectives. Mr Clarke said the ages of the men arrested were 17, 18, 19, 20, 21, 21, 22 and 32.
Mr Clarke added that they were not linked to Irish Republican terrorism or to the recent attack in Madrid.
“The men arrested are all British citizens,” he added.
“We know the overwhelming majority of the Muslim community are law-abiding and completely reject all forms of violence.
“Today at both local and national levels we have been holding discussions with community leaders and other representatives to address any concerns they may have.”
Mr Clarke added that today’s operations involve 700 officers and are part of continuing and extensive investigations into alleged international terrorism.
He said: “I must stress the threat from terrorism is very real and the public must remain watchful and alert.”
He added that the operations were complex and detailed and would take a considerable time to complete and therefore it would not be appropriate to give further details.
Mr Clarke said he realised the operation would create “intense media coverage”, which is why Scotland Yard have taken the unusual step of calling a press conference so early after the initial raids.
He asked for restraint from the media in reporting the police operations so as not to prejudice any future investigations.