A third of Islamic State (IS) fighters in Syria and Iraq is from Europe. According to the Austrian Federal Office against Terrorism and for Protection of the Constitution (BVT) there are at least two dozen Austrians among them, the news daily Kurier reports.
Most of the European extremists fly to Turkey from where they cross the border into Syria.
The IS headquarters is situated in the town of Ar-Raqqa in northern Syria.
According to local inhabitants, all hotels and guest houses are occupied by foreign fighters, among them approximately 50 fighters from Austria.
All in all there are 100 Austrians suspected by the BVT of fighting in Syria. Nearly all of them have migrant backgrounds, and a high proportion of them are Chechens.
Some of the fighters have already returned to Austria. The BVT has classified them as potentially dangerous. Around 20 fighters are believed to have died in combat.