It only took 19 terrorists to launch the attacks of 9/11: Security services identify 700 potential al-Qa’ida terrorists at large in Britain. (Hat tip: LGF readers.)

At least 700 people suspected of being involved in al-Qa’ida terrorist plots have been identified by MI5 and the police, The Independent understands.

There has been a threefold increase in the number of terror suspects identified by the security service, MI5, since the 11 September attacks in the United States in 2001, security sources have disclosed. …

Since the 2001 attacks in the United States, the number of identified al-Qa’ida supporters living in Britain who are considered a threat to national security has risen by 300 per cent, according to security sources. Although a total number has not been confirmed, sources have indicated that it is in the “high hundreds” and “far more” than the most recently quoted figure of 400. A Whitehall source last night put the total at “at least 700” and the police have quoted a figure of 200 in 2001. A security source said: “We are talking about radicals or plotters who would be of interest because of their potential threat to national security.

”There has been a 300 per cent increase since 9/11 in those types of individuals that we are looking at and are concerned about.“

A Whitehall source added: ”The service [MI5] is currently at a very high level of operational intensity in investigating plotting leading to mass casualty attacks in the UK. The current picture is very much like an extremist soup with a number of overlapping networks with a common cause. But these networks aren’t attached to each other. The picture is changing all the time. Many of the plotters are homegrown and currently living in the UK.”

Whitehall sources also disclosed that Islamist extremist groups in Pakistan have stepped up efforts to recruit young British Muslims visiting the country.