Turks.

This is coolbert:

These numbers seem to increase and multiply in an exponential number. The last figures I saw for the total ISIL combat force was about two thousand!

"More than 1,000 Turks fighting for the Islamic Caliphate"

"The number of Turkish citizens fighting under the umbrella of the Islamic State of Iraq and the Levant (ISIL) is slightly more than 1,000, according to Turkish officials, who admit that they are unable to learn the exact number. The estimated number of armed ISIL fighters is around 12,000 to 15,000, which shows that Turks make up just less than 10 percent of the jihadist group."

Turkey purports to be secular and wants admission into the European Union. That even a number of about 1,000 Turks have joined ISIL and are actively involved in the combat must be a worry to Ankara?

coolbert.