The draconian measure -- which generals say is designed to prevent Kurdistan Workers Party (PKK) fighters from crossing the border -- is being applied in the rural mountainous provinces of Siirt, Sirnak and Hakkari.

Turkey has launched several air raids since mid-December -- plus a week-long ground incursion into Iraq at the end of February -- against the PKK, which Ankara and much of the international community regards as a terrorist group.

The PKK has been fighting for self-rule in Kurdish-majority southeastern Turkey since 1984 in a conflict that has claimed more than 37,000 lives.

Ankara estimates that around 4,000 PKK rebels are taking refuge in Iraq's autonomous northern Kurdish region.