A record number of people have been arrested for terrorism-related offences, according to official figures.
The Home Office has announced that there were 379 arrests in Britain in the 12 months to June.
The figures include the dozens of arrests that took place following terrorist attacks in London and Manchester this summer.
Of these 379 terror-related arrests over the last year, 12 were made in connection with the Westminster attack, 23 related to the Manchester Arena bombing and 21 arrests were related to the attack some time later at London Bridge.
One arrest was related to the Finsbury Park attack in north London in June.
Sky News Home Affairs Correspondent Mark White said: “This 379 arrest figure is 68% higher than the 226 people who were arrested for the same period the year before.
“Significantly, it’s the highest number of arrests in a year since they began recording terror arrest statistics back in 2001 after the attacks on the Twin Towers and the Pentagon in the US.
“It has been an exceptional year in terms of the way in which the police operations and intelligence services have been gathering intelligence and trying to bring people to justice after three terrorist attacks in quick succession.”
A breakdown of the figures show that 54 of the arrested suspects were women – the largest female proportion on record – and 17 people held were under the age of 18.
There was also a sharp rise of 92% (from 66 to 127) in the number of white suspects detained.
While more than three quarters of the arrests were related to international terrorism, there was a sharp rise in the number of arrests for domestic terrorism (from 10 to 52).
The 420% increase in terrorism with no international or Northern Island related links comes amid mounting concern over far-right extremism.
The figures show that of those who have been arrested, 32% result in a charge.
Mark White explained: “Quite often what you see with the likes of a terrorist attack, a lot of people who are initially arrested – they could be family members, friends and associates of someone who has carried out an attack – but after questioning and detailed investigations these people are often released without charge.
“That’s why we’re looking at such a high number, but they are still pretty significant.”
Five hundred investigations, involving 3,000 individuals, are being run by the police and MI5 at any one time. At least 20,000 former “subjects of interest” are also kept under review.
Nineteen terrorist plots have been thwarted in the last four years, including six since the Westminster attack in March.
The current UK threat level for international terrorism is severe, which means an attack is highly likely.
(c) Sky News 2017: Record number of terror-related arrests