Kurdish militia fighters fired five mortars at an observation post in Idlib staffed by Turkish troops, the Anadolu news agency said. No casualties were reported and the mortars did not hit their target, it added.
In response, the Turkish army fired toward Kurdish militia-held positions around the town of Afrin, it added.
Turkish troops are deployed in Idlib as part of of an agreement with Iran and Russia to implement four so-called de-escalation zones in flashpoint areas around Syria.
Up until the deployment of Turkish troops in mid-October, Idlib had largely been controlled by Hayat Tahrir Al-Sham (HTS), a group led by Al-Qaeda’s former Syria affiliate.
The incident comes as Russian President Vladimir Putin prepares to host Turkish and Iranian counterparts Recep Tayyip Erdogan and Hassan Rouhani for summit talks on Syria in Sochi on Wednesday.
Turkey has repeatedly threatened to launch a military operation on Afrin, which is controlled by the Kurdish Peoples’ Protection Units (YPG) militia considered by Turkey to be a terror group.
Ankara views the YPG as the Turkish branch of the outlawed Kurdistan Workers’ Party (PKK) which has been waging an insurgency inside Turkey since 1984.
The PKK is blacklisted as a terrorist organization by Turkey, the US and the EU.
Turkish troops have repeatedly clashed with the YPG in Aleppo province, especially during Ankara’s incursion last year, but this is the first time such an incident has been reported in Idlib.
Russia, along with Iran, is the key supporter of Syrian President Bashar Assad while Turkey has backed the opposition seeking Assad’s ouster.
But Russia and Turkey have been working together since a 2016 reconciliation deal ended a crisis caused by the shooting down of a Russian war plane over Syria.
Analysts say that Erdogan will be keen to discourage Putin from backing the YPG in Syria at the Sochi talks, as Ankara seeks a say in post-war Syria after over six years of conflict.