The raid by "PKK/YPG terrorists" took place in Ras al-Ain, where Turkish soldiers were conducting reconnaissance and surveillance activities, the ministry said.

They returned fire and "confirmed targets were neutralised", it said in a statement, without giving details of when the attacks took place.

Turkey says the Syrian Kurdish People's Protection Units (YPG) militia is a "terrorist" offshoot of the outlawed Kurdistan Workers' Party (PKK).

The PKK, which has waged an insurgency against the Turkish state since 1984, is blacklisted as a terror group by Ankara and its Western allies.

But the YPG under the Syrian Democratic Forces (SDF) banner spearheaded the fight against the Islamic State extremist group in Syria with US support.

A 120-kilometre (75-mile) "safe zone" area between the Syrian towns of Tal Abyad and Ras al-Ain was part of an October 17 agreement between Ankara and Washington, involving the YPG's full withdrawal from the stretch.

American officials told Turkey on Tuesday that this had been completed but Turkish President Recep Tayyip Erdogan on Saturday suggested this was not the case.

"They sent us a written statement saying they had cleared the area after 120 hours, but unfortunately, they could not clean the area," Erdogan said in a speech in Istanbul.