The fighting erupted during a security operation launched near Eruh, in Siirt province, upon a tip-off that militants from the separatist Kurdistan Workers' Party (PKK) were in the area.

The fighting also left three soldiers wounded, they added.

In a separate incident, three soldiers sustained injuries when their vehicle was fired on as they were approaching a small hamlet in the neighbouring province of Sirnak.

PKK rebels were believed to be behind the incident, the sources said.

The PKK, listed as a terrorist organisation by Ankara and much of the international community, took up arms in 1984 for self-rule in Turkey's Kurdish-majority southeast, sparking a conflict that has claimed about 45,000 lives.