Terrorism in Great Britain: the statistics
The beginning of the millennium saw an increased political focus on the threat from international terrorism, heightened by the attack on the Twin Towers on 11 September 2001. Only one year before 9/11, new counter-terrorism legislation had been passed in the UK. Designed to reform and extend state powers found in previous counter-terrorism legislation, the Terrorism Act 2000 gave increased powers to the Home Secretary and the police. It moved the focus of counter-terrorism to all forms of domestic and international terrorism, rather than just Northern Ireland-related terrorism.
This briefing paper looks at statistics on terrorism since 2001.
With the exception of the number of deaths due to terrorism, data in this paper relates solely to Great Britain, that is England, Wales and Scotland. This is largely due to the application of different and more varied counter-terrorism legislation in Northern Ireland, and the different counting rules used in Northern Ireland’s terrorism statistics, making it difficult to compare with the rest of the UK.
The main source of data on terrorism in Great Britain is the Home Office’s quarterly statistical release, Operation of police powers under the Terrorism Act 2000. This is the source of data used in this briefing, except where specified. The data in this paper generally covers the financial year up to 2024/25 (unless otherwise specified).
Appendix tables are provided as a downloaded excel file.
Stop and SearchThe Terrorism Act 2000 introduced three new stop and search powers to assist police in the prevention, disruption and detection of terrorism: section 44, section 47A and section 43.
There were just under 460,000 stop and searches carried out under section 44 powers from 2007/08 to its repeal on 18 March 2011. Just over 3,000 searches (0.7%) led to an arrest being made.
Police used section 47A for the first time following the Parsons Green attack on 15 September 2017. 149 stop and searches were carried in total in 2017/18, of which five resulted in an arrest, three of these terrorism-related. No further stop and searches have been carried out under section 47A.
Data on the use of section 43 powers is only available for the Metropolitan Police Service. Between 2009/10 and 2024/25 there have been 9,212 stop and searches in London. 624 (7%) of these have resulted in a subsequent arrest.
Of those stopped and searched in London under powers conferred by section 43 between 2013/14 and 2024/25: 29% self-defined as White; 25% as Asian or Asian British; and 12% Black or Black British.
ArrestsBetween 11 September 2001 and 31 March 2025, there have been 5,734 terrorism-related arrests, 2,222 (39%) of which were made under section 41 of the Terrorism Act 2000.
There has been an increase in the number of young people arrested for terrorism-related offences in recent years. In 2002/03, just 3% (8) of those arrested were under 18 years of age, by 2024/25 this proportion had risen to 19% (43). Of the 345 under 18s arrested since 11 September 2001, half have been arrested since 1 April 2019.
Since 11 September 2001 there have been 105 different nationalities arrested for terrorism-related offences. Most (62%) declared they were a British national at the time of arrest.
Of those arrested for terrorism-related offences between 2014/15 and 2024/25, 41% were reported as being of Asian appearance, 37% White, 11% Black, and 22% Other or Not Known.
Prosecutions and convictionsOf the 1,423 individuals charged with a terrorism-related offence between 11 September 2001 and 31 March 2024, 87% (1,409) were proceeded against, and of those, 88% (1,244) were convicted.
Prison populationOn 31 March 2025, 108 (41%) of the 266 prisoners in custody for terrorism-connected offences defined themselves as White, 96 (36%) as Asian or Asian British, and 19 (7%) as Black or Black British.
The majority (62%) of prisoners in custody for terrorism-related offences on 31 March 2025 declared themselves as Muslim (166 prisoners). 53 prisoners (20%) were Christian.