§ Ms Oona King
To ask the Secretary of State for the Home Department how many people have been detained under United Kingdom anti-terrorism legislation since 11 September 2001; how many are in detention; how many of the total number detained have been charged; and how many are Muslims in each case. 
§ Mr. Blunkett
16 people have been certified and detained under Part 4 of the Anti-Terrorism Crime and Security (ATCS) Act, of whom 14 remain in detention. Anonymised details are provided at the Home Office website at: www.homeoffice.gov.uk/docs3/atcsa_detainees.html1258W
Under the Terrorism Act, Section 41 relates to the power of a constable to arrest, and detain for up to 14 days, without warrant a person whom he reasonably suspects to be a terrorist. A full 14 day detention is subject to judicial approval at various stages of the detention. From 11 September 2001 to 31 January 2004, 544 individuals were arrested and subsequently detained under this power.
In addition, six people have been convicted and detained for offences under that act. Of these, four have now left detention.
Schedule 7 of the Terrorism Act 2000 allows an examining officer at a port or border control post to detain a person for up to nine hours (starting from the time at which the examination begins) in order to determine whether the person has been involved in the commissioning, preparation or instigation of acts of terrorism. To date, 47 people have been detained under this power.
Details of convictions under the Terrorism Act 2000 are provided on the Home Office website at: www.homeoffice.gov.uk/docs3/tatc_arrest_stats.html
I do not believe that the religion of an individual is relevant to whether or not they may be involved in terrorism and this information is not collated centrally.