Syrian Kurdish fighters fired mortar rounds at a Turkish observation post in the northern Syrian province of Idlib on Monday, Turkey's Anadolu news agency reported.
There were no casualties in the attack near the Daret Azzeh region in Idlib, where Turkey is implementing a "de-escalation zone" to reduce conflict as part of an agreement reached with Russia and Iran.
Anadolu said Turkish forces retaliated after five mortar rounds were fired at the observation post.
Turkey sent troops into Syria last month to set up observation posts in the border province that is dominated by Al Qaeda-linked militants.
Turkey considers the Syrian Kurdish militia to be terrorists because of its links to Kurdish rebels fighting in Turkey's south-east.
President Recep Tayyip Erdogan warned on Friday that Turkey needed to send its troops into Syria to clear Kurdish fighters from the Afrin region of Aleppo, the province west of Idlib.
Turkey has been at odds with United States, its Nato ally, over Washington's support for the Syrian Kurdish militia, known as the YPG.
The YPG is the main component of the US-backed Syrian Democratic Forces, a multi-ethnic coalition of militias that has retaken large areas of the north Syria from ISIL over the past year.