Fifteen Kurdistan Workers Party (PKK) elements have been killed in Turkish air strikes in the Gara region northern Iraq on Friday, well informed sources said.
Ankara has warned it might launch a ground offensive into Qandil, where high-ranking PKK members are believed to be based.
President Tayyip Erdogan has vowed to "drain the terror swamp" there.
More than 40,000 people have been killed since the PKK launched its insurgency in Turkey in 1984. It is designated a terrorist organization by Turkey, the United States and European Union.