The Turkish military has lost contact with two soldiers taking part in operations in northern Syria, a statement carried by the state-run Anadolu news agency reports.
The report came just hours after an Islamic State-affiliated outlet, Amaq, said the extremist group had captured two Turkish soldiers west of the city of al-Bab, which it controls.
Ankara-backed forces are closing in on the city, located in Aleppo province.
The military statement said contact was lost in the afternoon and search operations were ongoing.
Turkey sent troops into northern Syria in August to back Syrian armed opposition members in battles against Islamic State and also Kurdish forces.
