FILE – In this still image grab taken from CCTV issued by the Metropolitan Police in London on Monday Feb. 23, 2015, 15-year-old Amira Abase, left, Kadiza Sultana,16, center, and Shamima Begum, 15, go through Gatwick airport, south of London, before they caught their flight to Turkey on Tuesday Feb 17, 2015. Little known to the wider world 18 months ago, the Islamic State extremist group has muscled its way into the international spotlight by carving out a self-declared caliphate in the heart of the Mideast, beheading its opponents and foreign journalists, and attracting radicalized youth as far afield as Paris, London and New York. (AP Photo/Metropolitan Police, File) NO ARCHIVE