Cardiff to Syria: How did two young brothers end up fighting for Isis?
24 June 2014 Last updated at 07:40 BST
The parents and friends of three men identified in the latest Isis propaganda video have expressed shock at their actions.
Security services estimate 500 young Britons have left the UK to fight for the militant Islamists, so where does their journey to extremism begin?
Graham Satchell reports.