Security forces initiated a search operation against the Kurdistan Workers' Party (PKK) rebels after the explosion on a road in a rural area of Mardin province, the sources said.

The PKK, listed as a terrorist group by Turkey and much of the international community, took up arms for Kurdish self-rule in 1984, sparking a conflict that has claimed some 45,000 lives.

The PKK announced in August 2010 a unilateral truce but threatened in February to end it, complaining of a lack of dialogue with the government in Ankara.

Fighting in Kurdish-dominated Anatolia, in southeastern Turkey, has lessened significantly since the truce, which the PKK had extended in November until general elections expected in June to push for a peaceful solution of the 26-year-old conflict.