The number of British Islamists who have gone to Syria to fight in the war there is in the “low hundreds”, a senior UK intelligence official says.
Andrew Parker, head of domestic intelligence service MI5, told a parliamentary hearing the conflict was attracting al-Qaeda UK sympathizers.
Their interaction with militant groups abroad was a “very important strand of the threat” the UK faced, he said.
One in 10 foreign militants in Syria is believed to be from Europe.
Most of them come from Saudi Arabia, Tunisia and Libya. MI5 has previously said that up to 200 British fighters are in Syria.
Last month, BBC News learnt that a group of 20 young men from the UK were fighting against forces allied to Syrian President Bashar al-Assad on the Turkish border.
According to the Centre for the Study of Radicalization at King’s College London, most British jihadists are in their 20s, university-educated and Muslims of British Pakistani origin.
Up to 20 people from Britain’s Sudanese community and several ethnic Syrians from the UK have also gone to fight in Syria. Read more