New CCTV pictures appear to show three UK schoolgirls on the Turkish leg of what is believed to have been their journey to join Islamic State in Syria. Shamima Begum and Amira Abase, 15, and Kadiza Sultana, 16, flew from London to Istanbul on 17 February. The images show them waiting at Bayrampasa bus station later that day. Scotland Yard believes the Bethnal Green Academy students are now in Syria. They are thought to have been met at the border by IS militants. The BBC understands that the girls waited in the offices of two bus companies at the station, before taking a bus to Urfa, close to the Syrian border, on 18 February. From there, they are thought to have been driven to a border crossing point by people smugglers. Time codes on the CCTV images suggest the girls were at the bus station, which is on the European side of Istanbul, for nearly 18 hours. The five images were taken between 20:27 local time (18:27 GMT) on 17 February and 13:22 (11:22 GMT) on 18 February. They had flown from Gatwick to Turkey after telling their parents they were going out for the day. The girls' families have made a number of emotional appeals for them to return home.