Turkey has confirmed that its military has attacked the main Kurdish force in northern Syria, a key ally of the United States in its efforts to defeat the Islamic State group.

The U.S.-supported Kurdish militia, known as the YPG, said the Turkish military shot at its forces deployed in the town of Tal Abyad twice on Sunday, using mostly machine guns. No one was injured in the shooting and the Kurdish forces didn’t return fire.

Turkish Prime Minister Ahmet Davutoglu confirmed that the military targeted the Kurdish forces in an interview with Turkey’s ATV television late Monday.

“We said the PYD will not go west of the Euphrates and that we would hit it the moment it did. We hit it twice,” Davutoglu said. The YPG is the fighting force of the PYD, or the Kurdish Democratic Party.

“Turkey cannot abandon its border, its fate to any country,” Davutoglu said.

Davutoglu did not elaborate. The two reports seemed to conflict each other with Davutoglu suggesting that the Turkish forces had hit the Kurdish forces west of the Euphrates river while the YPG said the attack was in Tal Abyad, which is east of the river.

Turkey is wary of the PYD, which is affiliated with Turkey’s Kurdish PKK rebels, who have waged a bloody insurgency in southeastern Turkey. The Kurdish capture of the majority-Arab town of Tal Abyad, and its subsequent inclusion under the semi-autonomous enclave has further irked the country.

The Kurdish forces have been a key ally for the U.S.-led coalition fighting the Islamic State group in Syria which Turkey is also a part of.

Turkey and the U.S. however, differ on whether the force is a terrorist organization. Both countries have labeled the PKK as a terror group but only Turkey considers the Syrian Kurdish forces as terrorists.

Kurdish fighters expelled Islamic State militants from Tal Abyad in June, dealing a major blow to the extremist group’s abilities to access supply routes across the Turkish borders.

Last week, Tal Abyad was declared an independent administration allied with the semi-autonomous Kurdish enclave in northern Syria.