There has been a surge in counter-terrorism arrests, with 338 people held across the UK in the past year, new figures reveal.
The numbers mark a 33 per cent increase on the year ending April 2014, with 56 per cent of those detained being under the age of 20.
The figures come as Scotland Yard’s top counter-terrorism officer warned there was a “massive threat on the streets of the UK” from jihadists who were returning from fighting with Islamic State and engaging in “barbaric” atrocities.
Assistant Commissioner Mark Rowley added that police were “wrestling to tackle” the dangers of “complex, organised plots” as well as more “chaotic” fundamentalists whose aims are constantly changing.
The Evening Standard reports that Rowley also warned of a “startling” trend of vulnerable young people to be tempted by terrorism, often lured by “recruiters and marketeers” despite police efforts to crackdown on them.
He said: “I won’t discuss live intelligence but you see a continuing picture of individuals who want to travel to Syria and individuals who want to stay at home and commit terrorism acts.
“There are significant numbers of each. I can think of cases involving individuals wrestling with ‘shall we travel or shall we stay here and do something?’ It’s a very real choice for some of these characters and those are some of the cases that we are currently investigating and prosecuting.”
Speaking about those who decide to remain in the UK, Rowley added: “we have individuals inspired by the rhetoric and ideology who either on their own or in small groups are thinking of acting and can be chaotic and volatile in their behaviour.
“Their plans and ambitions change on an almost daily basis — part of the challenge for us. Counter-terrorism officers in London are working flat out.”
Over 110 terror suspects are currently awaiting trial, four in five of whom are British citizens.