"We will continue to use with determination political, military, social and economic instruments" to combat the outlawed Kurdistan Workers' Party (PKK), Erdogan said in a monthly address to the nation aired on television.

"The only target of the cross-border operations the Turkish Armed Forces have conducted and will continue to conduct is the terrorist organisation's camps in the north of Iraq," he said.

"We have no other objective than protecting the security of our people, our borders and our unity," he added, stressing that Ankara supported Iraq's territorial integrity and stability.

The Turkish army has confirmed three air strikes on PKK positions in northern Iraq since December 16, in addition to a ground cross-border operation to stop a group of rebels seeking to infiltrate Turkey.

Officials in northern Iraq have reported two other air raids.

Faced with mounting PKK violence, Erdogan's government obtained a one-year parliamentary authorisation in October for cross-border military action against the PKK, which takes refuge in the mountains of northern Iraq and uses rear camps there as a springboard for attacks across the frontier.

The United States is providing Turkey, a NATO ally, with intelligence on PKK movements in Iraq.

At least 150 militants have been killed and more than 200 PKK positions destroyed in the raids so far, according to the Turkish military.

The PKK, listed as a terrorist group by Ankara and much of the international community, has waged a bloody campaign for Kurdish self-rule in southeast Turkey since 1984. The conflict that has claimed more than 37,000 lives.