One Turkish soldier was killed and three others wounded in a rocket attack on a tank close to the northern Syrian town of Jarablus on Saturday, Turkish military sources said, after Turkey launched a cross-border offensive this week.
The sources said the rocket was fired from territory held by the Kurdish YPG militia.
Rebels opposed to the Turkish intervention had earlier on Saturday denied there were Kurdish forces in the area. Turkey has said its campaign in Syria is targeting ISIS and preventing Kurdish forces extending their territory in north Syria.
The attack came as Ankara ratcheted up its cross-border offensive by saying it had launched air strikes on Kurdish forces and ISIS.
Turkey wants to stop Kurdish forces gaining control of a continuous stretch of Syrian territory on its frontier, which Ankara fears could be used to support the Kurdish militant group PKK as it wages its three-decade insurgency on Turkish soil.
Turkish security sources said two F-16 jets bombed a site controlled by the Kurdish YPG militia, which is part of the broader US-backed Syrian Democratic Forces (SDF) coalition. The sources also said the jets hit six ISIS targets.
Ankara’s opponents said Turkish forces had targeted YPG-allied forces but that no Kurdish forces were involved.
On the ground, Turkish-backed Syrian rebels fought forces aligned to the SDF near the frontier town of Jarablus. Forces opposed to Ankara said Turkish tanks were deployed, a charge denied by Turkey’s rebel allies.
Turkey launched its offensive into Syria on Wednesday, supporting its rebel allies with Turkish special forces, tanks and warplanes. It seized control of Jarablus from Islamic State seeking to stop any Kurdish forces moving in first.
Saturday’s use of warplanes against what Turkey said was a Kurdish YPG militia target highlights its determination to prevent any Kurdish territorial expansion in north Syria.
Any action against Kurdish forces in Syria puts Turkey at odds with its NATO ally the United States, which backs the SDF and YPG, seeing them as the most reliable and effective ally in the fight against ISIS in Syria.
It adds complexity to the Syrian conflict that erupted five years ago with an uprising against Syrian President Bashar al-Assad and has since drawn in regional states and world powers.
The Kurdish-led administration that controls parts of northern Syria said Turkish tanks advanced on al-Amarna and clashed with forces of the Jarablus Military Council. But the Kurdish administration said no Kurdish forces were involved.
However, the leader of one Turkey-backed rebel group gave a rival account. He told Reuters the rebels battled the Kurdish YPG around al-Amarna and denied any Turkish tanks took part.
Turkish security forces simply said Turkish-backed forces had extended their control to five villages beyond Jarablus.
A video released by Turkey’s military showed the Turkish Red Crescent distributing food and aid to people in Jarablus, with the help of Turkish troops. It also showed what appeared to be Turkish-backed rebels flicking v-for-victory signs in the town.
The newly formed Jarablus Military Council has said it was made up of people from the area with the aim of capturing the town and the surrounding region from ISIS militants. However, the Turkish-backed rebels seized Jarablus first.
Several militias under the SDF banner pledged support to Jarablus Military Council after it reported the Turkish bombing.
The Northern Sun Battalion, an SDF faction, said in a statement it was heading to “Jarablus fronts” to help the council against “threats made by factions belonging to Turkey”.
Tension has mounted in Syria’s Aleppo region in the past year between the US-backed Kurdish YPG force and its allies on one hand and Turkish-backed rebel groups on the other. The two sides have clashed on several occasions.