British counter-terrorism officials are monitoring 3,000 extremists in the UK who they fear could commit acts of domestic terror or become future “Jihadi Johns”.
Many will never have travelled abroad or been official members of terrorist organisations — underscoring the burgeoning problem facing intelligence and security agencies across Europe in trying to track radical communities of home-grown terrorists.
The disclosure follows the unmasking of a Londoner, Mohammed Emwazi, this week as the hooded murderer — nicknamed Jihadi John by the press — responsible for some of the most barbaric killings perpetrated by the Islamic State of Iraq and the Levant (Isis).
The figure of 3,000 is significantly higher than previous estimates. In late 2007, Jonathan Evans — now Lord Evans, and then director-general of Britain’s domestic security service MI5 — said officers were monitoring 2,000 individuals.
The number of subjects of interest (“SoIs”), as potentially violent extremists are known in MI5 parlance, had been stable until recent months. But the rise of Isis has greatly expanded their ranks.
Senior Whitehall security officials, who specified the current number of extremists under watch on condition of anonymity, told the Financial Times that there was now real concern over the impact that social media were having on radical individuals in Britain and the new ability to magnify the effect and appeal of the eruption of jihadism across the Middle East.
The Home Office declined to comment.
The focus of counter-terrorism efforts in Europe until now has been on preventing citizens from travelling to Syria and Iraq to join terror groups. An estimated 3,000 Europeans have travelled to fight as jihadis there, including more than 500 Britons.
But individuals who remain at home are increasingly being seen as high-priority targets for monitoring as the incidence of “lone wolf” terror attacks grows and a legal crackdown on extremism across Europe raises tensions.
They are becoming harder to track, too, say British officials, because they are less and less likely to be members of groups or well-connected networks.
One senior security officer described the problem as like trying to follow the random “Brownian motion” of particles in a teapot.
“There have always been a lot of people [under watch]. But the perception for a long time was that the numbers had plateaued,” said Raffaello Pantucci, an expert on UK extremism and director of international security studies at the Royal United Services Institute think-tank. “Now there is a whole new layer on top of that because the noise from Isis in Syria and Iraq is so loud it is attracting others.”
The risk of such individuals carrying out “lone wolf” attacks is increasing, said Mr Pantucci.
A spate of such terror attacks in countries around the west in recent months has set security agencies on high alert. In Europe, officials have been fearful that a cycle of violence could take hold as attacks such as the Charlie Hebdo murders in Paris encourage others to act.
The issue is a particularly sensitive one for MI5. Since the murder of Fusilier Lee Rigby in Woolwich in 2013, the agency has sought to place greater emphasis on tracking low-level extremists who are not necessarily members of known cells or networks but who could pose a risk.
A joint project with Scotland Yard to tackle the problem is known by a codename as project “Danube”. It replaces an earlier similar effort known as “Amazon”, which was mothballed in 2010 because of the complexity and size of the task it faced.
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