"The Secretary-General condemns the killing of 15 soldiers in Turkey yesterday (Friday), in the latest attack attributed to the PKK (Kurdistan Workers' Party) operating out of northern Iraq," she said in a statement.

"He expresses once again his deepest sympathies with the Government and people of Turkey in the face of terrorist violence ... (and) urges continued cooperation between the Governments of Turkey and Iraq to address this threat and to promote peace and stability along their border," Montas added.

Friday's attack came just before the Turkish parliament was set to vote on extending by one year the government's mandate to order military strikes against PKK bases in northern Iraq.

The PKK -- considered a terrorist group by Turkey, the United States and the European Union -- has been fighting for a separate state in the mainly Kurdish southeast of Turkey since 1984.

The conflict has claimed some 44,000 lives, according to figures recently released by the Turkish army.