Turkish-backed rebels launched an offensive on October 15 to try to capture the Syrian town of Dabiq, a symbolically important stronghold of the Islamic State (IS) extremist group.
Turkish President Recep Tayyip Erdogan confirmed that Turkish-backed fighters were advancing on Dabiq in televised comments in the Black Sea province of Rize.
The Britain-based Syrian Observatory for Human Rights said the attack took place following heavy shelling. The rebels captured three nearby villages, encircling Dabiq and cutting of all supply routes.
The town lies about 10 kilometers from the Turkish border.
Dabiq, occupied by IS since August 2014, is important to IS propaganda because militants believe that Dabiq will be the scene of an apocalyptic battle between Christianity and Islam.
Turkish troops have been present in northern Syria since August in order to help opposition forces recapture IS strongholds and stop the advance of the U.S.-backed Syrian Kurdish militia, which Turkey sees as an extension of its outlawed Kurdish separatists.
The offensive came as U.S. Secretary of State John Kerry was meeting with Russian Foreign Minister Sergei Lavrov in Switzerland in a new effort to try to end the Syrian conflict.