Terror-related arrests hit record high as threat gathers momentum
Terror-related arrests have surged to a new record high, with suspects held at a rate of more than one every day as security services confront a "momentum shift" in the threat.
A senior detective warned there is no such thing as a "typical terrorist" after official figures showed rises in numbers detained across ethnicities and age groups.
There were 379 arrests for terrorism-related offences in Great Britain in the year ending June 2017, the highest number in a 12-month period since data collection began in 2001.
Arrests jumped by 68% year on year, with the increase partly driven by activity mounted amid a flurry of terrorist incidents in four months earlier this year.
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.
Deputy Assistant Commissioner Neil Basu, the senior national co-ordinator for counter-terrorism policing, said: "We would describe this as a shift not a spike.
"There has been a momentum shift since the attacks in London and Manchester and that simply means there are more people out there prepared to attack."
The senior officer said the figures should reassure the public that police and MI5 are working "night and day" to disrupt and arrest people "who are determined to hurt us".
The new Home Office data also reveals that in the year to June:
:: Fifty-four female terror suspects were arrested - at 14% of the total, this was the largest proportion on record;
:: Seventeen of those held were aged under 18, which is the highest number for any July-June period in the current data series;
:: There were rises in the number of arrests across all ethnic groups, including a 92% jump, from 66 to 127, in the number of white suspects detained.
Mr Basu said the figures show there is "no such thing as a 'typical' terrorist" and urged the public to report any suspicious activity to police.
He told the Press Association: "We've seen people from all walks of life.
"We've seen people young and old, male and female, we've seen the highly educated, the illiterate.
"We've seen people with mental health problems, people with previous criminal histories, we've seen people we've had no knowledge of before."
It emerged earlier this year that counter-terror agencies 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.
Mr Basu said: "It should be obvious from those figures that the scale is a huge challenge. We are never complacent, we are looking at our systems and our processes.
"Across that scale people will be at various levels but the public shouldn't expect us to be able to watch everybody all of the time.
"We have to constantly balance what is a proportionate and necessary investigation against the numbers we are looking at and I am very confident we will continue to do that to the best of our ability."
The new figures show a 60% jump in arrests linked to international terrorism, from 184 to 294.
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.
There was also a leap in 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.
Of the 379 arrests, 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) or faced "alternative action" (11). Two cases were pending at the time the statistics were compiled.