London: The father of a British teenager who travelled to Syria to join jihadists has alleged that 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 believed he was now fighting with the Islamic State of Iraq and the Levant (ISIS), the militant-led group that has made rapid advances through Iraq in recent weeks.
Kalantar said his son was sent "down this road" by an imam - who denied the allegations.
Up to 500 Britons are thought to have travelled to the Middle East to fight in the conflict, officials say.
Kalantar said he worries about his son Ali "every minute" and that his grief is "limitless".
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 BBC said the imam has completely denied the allegations.
Ali is believed to have travelled to Syria with Rashed Amani, also 18, who had been studying business at Coventry University.
Rashed`s father, Khabir, said family members had travelled to the Turkish-Syrian border in the hope of finding the boys, but came back "empty-handed" after searching for more than two weeks.
He said he did not know what had happened to his son, who he fears has joined ISIS.
"Maybe somebody worked with him, I don`t know. Maybe somebody brainwashed him because he was not like that," he said.
The third teenager, Moh Ismael, is also believed to be in Syria with his friends. He is understood to have posted a message on Twitter saying he was with ISIS.
The UK last week banned five Syria-linked jihadist groups - including ISIS.
Under this, it will now be an offence to be a member of any of the groups in the UK.