A Turkish soldier was killed on Tuesday by fire from Islamic State-held territory on the Syrian side of the border and another soldier was missing, the local governor said.
The incident took place in the border region of Kilis and the soldier died of his wounds in hospital after an exchange of fire with smugglers, Kilis governor Suleyman Tapsiz said, cited by Dogan news agency.
Another soldier was missing following the incident, Tapsiz said, without elaborating.
Ankara has launched a two-pronged "anti-terror" offensive against jihadists in Syria and Kurdish rebels in northern Iraq after a series of attacks on Turkish soil, including a suicide bombing blamed on IS that killed 32 pro-Kurdish activists in the town of Suruc in July.
Turkish tanks opened fire on targets controlled by IS jihadists in Syria for the first time in July after two Turkish soldiers were killed in Kilis by shots from the Syrian side of the border.
Turkish warplanes have for the first time joined raids by the US-led coalition against IS in Syria after Washington urged Ankara to play a full role in the battle against the jihadists.