It is only a matter of time before terrorists attack London's financial heartland, the police officer responsible for the district says.
James Hart, commissioner of the City of London Police, told the Financial Timesthere had been "hostile reconnaissance" of the City on several occasions since the September 11th attacks in 2001.
James Hart, commissioner of City of London Police
He told the newspaper: "Every successful terrorist group pre-surveys its target. There's no doubt we've been subject to that surveillance and that sort of thing has been successfully disrupted."
He pointed out that the area had been a terrorist target for three decades, saying: "Look at the number of time we were hit by the IRA. I think (another attack) is a question of when rather than if."
He said potential targets that had been staked out included iconic sites, businesses and prominent buildings, "anywhere where the maximum damage can be inflicted on the financial systems of the City of London and (where you can) associate that with mass murder and maximum disruption."
Mr Hart estimated that only 50 per cent of businesses had contingency plans in place in case of an attack.
He said the mindset of would-be terrorists meant the financial centres of western governments were prime targets.
"If you want to hurt the Government, hurt people at the same time, and you want to cause maximum disruption...where better to hit than at the financial centre?"
The commissioner said there had been no arrests by police investigating surveillance by terrorist groups, but added that all information had been passed on to intelligence agencies.
He said the security cordon around the Square Mile had been extended as far as was practicable.
PA