Turkey is a main point of departure for Syrians and others seeking a better life in Europe, with many setting off for Greece's eastern islands aboard flimsy boats.
Meanwhile, Hungarian police have used tear gas after hundreds of migrants broke through a razor wire fence on the border with Serbia.
The police stopped the crowd, who threw plastic water bottles at them. There were no reports of injuries. Several people were seen with tears in their eyes from the gas.
The crowd coming in from the Serbian border town of Horgos remained in front of the gate facing the police cordon. A Hungarian water cannon was parked facing them.