At least five Turkish soldiers were killed on Monday as the Syrian forces shelled an air base taken by the Turkish forces in the northwestern province of Idlib, activists said.

Russia said on Tuesday it would not allow clashes between Ankara and Damascus as Turkey presses a military offensive against Kurdish forces in northern Syria.

Turkish forces have reached the outskirts of the town of Afrin after a weeks-long campaign against a Kurdish militia in northwest Syria, the Syrian Observatory for Human Rights war monitoring group said on Saturday.