ISTANBUL (Reuters) - Security footage appears to show three British schoolgirls, believed to be on their way to join Islamic State militants, waiting for hours at a bus station in Turkey before traveling to a city near the Syrian border, media reported on Sunday.
British police and the girls' families have issued urgent appeals for their daughters to return home after they flew to Istanbul from London on Feb. 17. Friends Amira Abase, 15, Shamima Begum, 15, and Kadiza Sultana, 16, are thought to have since entered Syria, British police have said.
European governments have called on Turkey to stem the flow of foreign fighters to Syria, and British Prime Minister David Cameron has urged social media firms to do more to deal with online extremism, saying the girls appeared to have been radicalized "in their bedrooms."
The CCTV pictures, dated Feb. 17 and Feb. 18, are from Bayrampasa bus station on the European side of Istanbul, which the girls reached by metro from the airport, Milliyet newspaper said, citing police sources.
They say the girls spent 18 hours at Bayrampasa before boarding a bus to travel to Sanlifurfa, 50 km (30 miles) from the Syrian border region controlled by Islamic State militants.
Turkish police are trying to identify people seen in the footage helping the girls with their luggage at the bus station.
Turkey has complained that Britain was late in notifying it about the girls' arrival, a charge London rejects.
British police said on Sunday that about 60 young women and girls were now believed to have traveled to Syria from Britain, including about 22 in the last year.
"When I say young, all but four of those 22 were aged 20 or younger," Helen Ball, deputy assistant commissioner of London's Metropolitan Police, told BBC TV.
"The last five who have traveled were aged 15 and 16, so this is a growing problem and it is one of real concern."
British security agencies estimate that about 600 British Muslims have traveled to the region to join the conflict, some with Islamic State, the extremist Sunni Muslim group that controls a swathe of territory in Syria and Iraq.
(Reporting by Ayla Jean Yackley; Additional reporting by Andrew Osborn in London; Editing by Janet Lawrence and Susan Fenton)