Terror-related arrests have surged to a new record high as security services confront an unprecedented threat, new figures reveal.
There were 379 arrests for terrorism-related offences in Great Britain in the year ending June 2017, a rate of more than one a day and the highest number in a year since data collection began in 2001.
The number of terrorism-related arrests in Great Britain in 12 months to June 2017 (PA Graphics)
The tally includes dozens of individuals held in swoops in the wake of attacks in London and Manchester.
Arrests jumped by 68% year on year, with the increase partly driven by activity mounted amid a flurry of terrorist incidents between March 22 and June 19.
The 379 total includes 57 arrests made in connection with the Westminster (12 arrests), Manchester (23 arrests), London Bridge (21 arrests) and Finsbury Park (one arrest) attacks.
The number of terrorism-related arrests in Great Britain (PA Graphics)
The Home Office data also reveal that 54 female terror suspects were arrested in the year to June.
At 14% of the total, this was the largest proportion on record.
There were increases in the number of arrests across all age groups compared with the previous year.
Seventeen of those held were aged under 18, which is the highest number for any June-July period in the current data series.
Following the Westminster Bridge attack, 12 people were arrested (Rick Findler/PA)
There were also rises in the number of arrests across all ethnic groups, including a particularly sharp jump of 92%, from 66 to 127, in the number of white suspects detained.
It means the white ethnicity group accounted for a third (34%) of all terror-related arrests over the year.
The number of individuals arrested for suspected international terrorism jumped by 60%, from 184 to 294 compared with the previous year, and accounted for more than three quarters of all the arrests.
This category refers to activity linked to or motivated by any terrorist group that is based outside the UK which operates in and from third countries, such as Islamic State.
23 people were arrested in connection with the bomb at Manchester Arena (Jonathan Brady/PA)
There was also a leap in the number of arrests for “domestic” terrorism, up from 10 in the year to June 2016 to 52 in the latest period.
Domestic terrorism refers to activity where there are no links to either Northern Ireland-related or international terrorism.
The figures are not broken down further but the disclosure comes amid mounting concern over far-right extremism.
Of the 379 arrests in the 12 months to the middle of this year, 123 resulted in a charge, including 105 where suspects were charged with terror-related offences.
Around half (189) of those held were released without charge, while others were released on bail (54), faced “alternative action” (11) and two cases were pending at the time the statistics were compiled.
21 people were arrested after the attack on London Bridge in June (Dominic Lipinski/PA
The latest arrest figures chime with repeated warnings that the scale of the threat from violent extremism is unprecedented.
Police and MI5 are running 500 investigations involving 3,000 individuals at any one time, while there are also 20,000 former “subjects of interest” whose risk must be kept under review.
Since the middle of 2013, authorities have thwarted 19 plots, including six since the Westminster attack.
Deputy Assistant Commissioner Neil Basu, the senior national co-ordinator for counter-terrorism policing, said: “There is no doubt that since March and following the attacks in London and Manchester we have seen a shift-change in momentum.
“But while the terrorist threat has increased in recent months, so has our activity; reflected by this significant increase in arrests.”