The father of a British teenager who travelled to Syria to join jihadists believes his son was radicalised by an imam at a UK mosque. Rahim Kalantar told the BBC his son Ali, 18, travelled to Syria with two friends from Coventry in March, and he believed he was now fighting with ISIS. He said he believed Ali - who was planning to study computer science at university - had been radicalised during classes at a mosque after evening prayer. ‘He [the imam] encouraged them and sent them down this road,’ he said. The iman has denied these allegations.  Up to 500 Britons are thought to have travelled to the Middle East to fight in the onflict, officials say.