British forces have thwarted attempts to carry out more terror attacks since the July 7 London bombings and a botched bid to repeat them on July 21, the capital's police chief said. "The security service and the Met have prevented other attacks in the last few weeks," Metropolitan Police Commissioner Sir Ian Blair said in an article in The Sun newspaper.
"The sky is dark. Intelligence exists to suggest that other groups will attempt to attack Britain in the coming months," he said.
Sir Ian said it could take weeks or months to understand material that was found.
"One case involved an encrypted computer, which was the equivalent of 60,000 feet of paper. Was there a vital clue in there somewhere? Yes, but we were fortunate that it was pretty near the beginning, otherwise we would never have found it within the current time limit."
He added that police chiefs were united in supporting an extension of detention for terrorist suspects to 90 days, if officers were to defeat those planning further carnage.
The issue is to be debated again in the House of Commons this week, with opponents urging Home Secretary Charles Clarke to drop the proposal to hold terror suspects for up to 90 days without charge.
Blair said detention must have rigorous scrutiny by a judge every seven or 14 days, to confirm that continued detention was appropriate.
The victims of the July 7 bombings in London were remembered at a national memorial service on Tuesday with a renewed call to respect all human life in the face of indiscriminate violence.
Some 2,300 people, led by Queen Elizabeth II and Prime Minister Tony Blair, attended the service at St Paul's Cathedral, with thousands more watching outside and in Trafalgar Square on giant screens.
But relatives of some of the 52 victims of the worst terror attack on British soil stayed away, expressing anger at a lack of practical support and adequate compensation from the government since the atrocities.
