A Russian airstrike killed 10 people, including three children, in Azaz, near Syria's border with Turkey, the Syrian Observatory for Human Rights reported, as Ankara pledged to protect rebel positions in the area.
"We will not allow Azaz to fall," Prime Minister Ahmet Davutoglu was quoted by the state-run Anadolu news agency as saying while traveling to Kiev. The town sits just over the border from Turkey and is a key supply route for rebels.
He also warned the Syrian Kurdish militia not to advance further in the region, after Turkey shelled their positions repeatedly in recent days.
"If they approach Azaz they will face the most severe reaction," he said, pledging to destroy an airbase the Kurdish YPG militia captured if they do not withdraw.