One Turkish soldier was killed and another was wounded after an attack by the Syrian Kurdish YPG militia in northeast Syria's Tel Abyad, the defence ministry said, RTE reports.
It comes despite a deal to pause military operations as militants withdraw from the area.
Turkey agreed with the United States on Thursday to pauseits offensive into northeastern Syria for five days to allow theYPG to withdraw out of a planned "safe zone".
The fragile truce had so far held up.
In a statement, the defence ministry said an attack by the YPG with anti-tank and light weapons had struck Turkish soldiers carrying out a reconnaissance and surveillance mission in Tel Abyad.
It said the attack was retaliated, and added that Turkey remained committed to the truce deal despite the violations.
