Authorities in Turkey say they have detained an alleged spy suspected of helping three British schoolgirls join the extremist group
The suspect is a Syrian national who works for the intelligence service of a country that is part of the U.S.-led coalition fighting Islamic State, Foreign Minister Mevlut Cavusoglu told reporters in Ankara on Friday.
"The situation is so complicated," he was quoted as saying by Today's Zaman, a Turkish newspaper.
Cavusoglu, who first disclosed the arrest in an interview Thursday, did not identify the country that the suspect was believed to be working for, but said it was not the U.S. or a member of the
A Turkish government official told the Associated Press that the suspect had been in custody for more than a week.
The British Foreign Office said it was aware of the arrest and the girls' families had been informed.
British police say the three teens -- Amira Abase and Shamima Begum, both 15, and Kadiza Sultana, 16 -- flew from London to Istanbul on Feb. 17. Surveillance footage shows them waiting at a bus depot for nearly 18 hours before boarding a bus to the Turkish city of Sanliurfa, close to the Syrian border.
From there, they are believed to have been transported into Islamic State-controlled territory by smugglers. Syrian activists say the trio is in Raqqa, capital of the militant group's self-styled caliphate.
Their families say they had no idea the girls had been radicalized and have pleaded with them to return home.