Turkish warplanes launched a massive air operation early Tuesday against bases of the outlawed Kurdistan Workers' Party (PKK) in northern Iraq, killing between 35 and 40 rebels, the state-run Anatolia news agency said Tuesday.

More than 50 Turkish jets were involved in the six hours of raids, killing "35 to 40 terrorists according to preliminary findings", Anatolia said. The overnight operation came after 16 Turkish soldiers were killed in the Kurdish dominated southeast of the country on Sunday in an attack blamed on the PKK.

Thirty-five F-16 jets and 18 F-4 phantoms took part in the heavy raids on a score of PKK targets, according to the news agency.

After initial silence over the scale of the toll, the Turkish army announced on Monday that 16 of its troops had been killed in the roadside bomb attack carried out by the PKK, which is designated as a terrorist organisation by Ankara and much of the international community.