London Telegraph 
Sunday, Nov 9, 2008
Secret enclaves of al-Qaeda extremists based in London, Birmingham and Luton are planning mass-casualty attacks in Britain, according to a leaked Government intelligence report.
The document, which was drawn up by the intelligence branch of the Ministry of Defence, MI5 and Special Branch, states that “some thousands” of extremists are active in the UK. They are predominantly UK-born and aged between 18 and 30, and many are believed to have been trained in overseas terrorist camps.
Under the heading “International Terrorism”, the report, which is marked “restricted” states: “For the foreseeable future the UK will continue to be a high-priority target for international terrorists aligned with al-Qaeda. It will face a threat from British nationals, including Muslim converts, and UK-based foreign terrorists, as well as terrorists planning attacks from abroad.”
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The report states that the threat from the Islamist extremist community in the UK is “diverse and widely distributed” but adds that the numbers of terrorist in Britain is “difficult to judge”.
The document does state, however, that the Joint Terrorism Analysis Centre, which is based in MI5’s headquarters at Thames House in London, estimates that there are “some thousands of extremists in the UK committed to supporting Jihadi activities, either in the UK or abroad”.
A year ago Jonathan Evans, the director general of MI5, said in a speech that his organisation had identified that there were at least 2,000 individuals who posed a threat to national security and public safety.
Since 2001, over 1,200 terrorist suspect have been arrested, over 140 have been charged and more than 45 have been convicted of terrorism offences, according to Home Office figures. It is also estimated that there are some 200 terrorist networks functioning in Britain today who are involved in at least 30 plots.