ISIS threatens to kill British jihadis who want to return home: At least 30 Britons planning to flee Syria after ex-private schoolboy from Portsmouth is killed fighting for terror group

A former Guantanamo Bay detainee, who has contacts among Syrian rebel groups, claimed that he knew of more than 30 Britons who had become linked to the terrorists but now wanted to return to the UK. He said that any jihadis who wanted to quit the terror group 'could be subject to disciplinary measures which could include threats of death or death'. The revelation comes after it emerged that Mehdi Hassan, 19, (left) who attended a private Catholic school in Portsmouth, Hampshire (bottom right), was killed in the Syrian Kurdish town of Kobani after fleeing Britain to fight for ISIS. The former public schoolboy was one of five British jihadists who were caught on CCTV at London's Gatwick Airport last October as they travelled to Turkey (top right) before slipping across the border to Syria