MOSCOW, February 3 (Sputnik) — Up to 4,000 people purportedly linked to Islamic extremists currently threaten the United Kingdom, London Mayor Boris Johnson said Tuesday.
"At any one time, there are a large number of people – perhaps in the low thousands – who do present some measure of potential risk," he told LBC Radio.
Johnson estimated the number of Islamic extremists at about 3,000 to 4,000, without confirming where the numbers came from.
Since the beginning of the civil conflict in Syria in 2011, some 15,000 foreign fighters have entered the country to join different extremist groups, according to UN estimates. In November 2014, British parliamentarian Khalid Mahmood said that about 2,000 Britons were fighting alongside jihadists in Iraq and Syria, exceeding the estimates of UK authorities fourfold.