The warning came in a general staff statement, carried by the Anatolia news agency, which said that Kurdish security forces in northern Iraq had earlier Friday harassed Turkish soldiers at a checkpoint in the city of Sulaymaniyah.

"Everybody should know and understand that our elements on duty in this area are sons of the Turkish nation and the heroic Turkish army," the statement said.

"The slightest unethical act or behaviour towards them will be taken as one against the entire Turkish republic and the Turkish armed forces and will face a response at the highest necessary level," it added.

The Turkish army keeps a contingent of a few thousand soldiers in a region of northern Iraq close to the Turkish border to monitor the activities of Turkish Kurdish rebels holed up in bases in the mountainous region.

The general staff said Turkish soldiers travelling in civilian clothes had been stopped at a checkpoint in Sulaymaniyah at noon Friday where local Kurdish forces verbally abused them and pointed their guns at them.

The incident ended when Turkish soldiers introduced themselves, the statement said, describing the event as a "misunderstanding".

The Turkish soldiers returned to their bases safely, it added.

The army statement came two days after the autonomous Iraqi Kurdish government took charge of security issues in their region in a transfer of command from the US-led coalition.

The development is being closely monitored by Turkey, which charges that thousands of rebels from the outlawed Kurdistan Workers' Party (PKK) have found refuge in the mountainous region.

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

Ankara says the Iraqi Kurds tolerate -- and even assist -- PKK rebels who, it charges, enjoy free movement and obtain weapons and explosives there for attacks across the border.

Turkey has long been frustrated by US and Iraqi reluctance to stamp out the PKK presence in the region and has even threatened to carry out a cross-border operation if Washington and Baghdad fail to do so.

The chief of the Turkish general staff, General Yasar Buyukanit, said on Thursday that he favored an incursion into northern Iraq to clean up PKK bases, but added that Turkish troops could find themselves fighting Iraqi forces in such an operation.

"The political authorities must determine whether, once we go in (to northern Iraq), we act only against the PKK or if something will happen with Barzani as well," he said, referring to Massud Barzani, who heads the Kurdish autonomous region's government.

Vocal support for a Turkish incursion has been growing since PKK activities in the southerast increased with the arrival of spring and a suicide bomb attack in Ankara, blamed on the PKK, killed six and wounded more than 100.

But Foreign Minister Abdullah Gul said last week Turkey had no immediate plans for such action.

Washington has warned Ankara against a cross-border operation, wary that such a move may destabilise a relatively peaceful region in the conflict-torn country.