Three Turkish soldiers have died in a new offensive against Kurdish militants in northern Iraq, the Turkish defence ministry said on Thursday.

Turkey on Wednesday launched an operation dubbed "Claw-Eagle 2" against Kurdistan Workers' Party (PKK) rebels holed up in the northern Iraqi region of Dohuk.

Two Turkish soldiers died and two others were wounded Wednesday in clashes with the "terrorists", the defence ministry said.

Another soldier was killed on Thursday, said the ministry, without proving casualty figures for the PKK.

The PKK, listed as a terror group by Turkey and much of the international community, has for decades used Iraq's mountainous areas as a springboard for its insurgency against the Turkish state. 

The Turkish army regularly conducts cross-border operations and air raids on PKK bases in northern Iraq.

Turkey launched its first "Claw-Eagle" operation in June.

Last month, Defence Minister Hulusi Akar visited Baghdad and northern Iraq where he said Turkey intended to eliminate PKK attacks in the region to ensure border security and regional peace.

The Kurdish insurgency against the Turkish state is believed to have killed tens of thousands of people since being launched in 1984.