Northern Iraqi officials said a few hundred Turkish troops crossed the border early Tuesday and reportedly penetrated several kilometres (miles) inside Iraq from an area called Seed Qan.

"Our army is doing what is necessary and will continue to do so.... Terrorism is not a local phenomenon, it is international," Prime Minister Recep Tayyip Erdogan said when asked to confirm the incursion.

The separatist Kurdistan Workers' Party (PKK) "is threatening our national unity and we are using our rights stemming from international law against this terrorist organisation," he said.

The incursion followed Turkish air and artillery strikes Sunday on positions inside Iraq along the Turkish border and in the Qandil mountains to the east where the PKK is known to have bases.

It was the first reported land operation by Turkish troops in Iraq since tensions between Ankara and Baghdad rose in October over the safe haven the PKK enjoys in northern Iraq.

President Abdullah Gul responded in similar terms when questioned on the issue.

The military "is doing what is necessary in the fight against terrorism," the CNN Turk news channel quoted Gul as saying in the central city of Konya. "Turkey has only one target (in Iraq), and that is terrorism," he said.

Erdogan, speaking in Ankara at a joint news conference with Macedonian counterpart Nikola Greuvski, insisted Turkey had no claims against Iraq's territorial integrity nor any hostility for its civilians.

He added, "but there are PKK camps there.... (The PKK) are terrorists, they are our enemies."

Ankara, he said, has garnered international support against the PKK, listed as a terrorist organisation by Turkey, the European Union and the United States.

Turkish chief of staff General Yasar Buyukanit has said the United States gave tacit consent for Sunday's air raids by providing "intelligence" and opening Iraqi airspace.

Faced with mounting PKK violence, Erdogan's government secured in October a one-year parliamentary authorisation for cross-border strikes in northern Iraq, where the PKK has camps serving as a springboard for attacks across the border.

The PKK has waged a bloody campaign for Kurdish self-rule in southeast Turkey since 1984. The conflict has claimed more than 37,000 lives.

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