Iraqi Ambassador Sabah Omran "gave us an official note requesting information about what measures are being taken at the border," a Turkish diplomat said.

She denied media reports that the note included a protest against cross-border operations by Turkish commando units pursuing armed rebels of the Kurdistan Workers' Party (PKK), which has fought for Kurdish self-rule in southeast Turkey since 1984.

"There are no such operations and the note did not include such a protest," the diplomat said, speaking on condition of anonymity.

Officials at the Iraqi embassy were not available for comment.

Thousands of armed militants of the PKK have found refuge at bases in northern Iraq since 1999, when the group declared a unilateral ceasefire after the arrest of their leader, Abdullah Ocalan.

The PKK, which called off the truce in June 2004, has markedly stepped up violence this year and officials say they have begun to infiltrate Turkey in growing numbers, as they do each year with the advent of spring.

Foreign Minister Abdullah Gul said Tuesday after talks with US Secretary of State Condoleezza Rice that Turkey had no plans for a cross-border operation, but he reiterated Turkey's unhappiness with US and Iraqi cooperation against the PKK, blacklisted as a terrorist group by both Ankara and Washington.

The Turkish army conducted incursions into Iraq before the US-led invasion of the country in 2003.

The NTV news channel said the Iraqi note, as well as a similar note given to to the Turkish embassy in Baghdad, included a protest over "small-scale hit-and-run operations" by Turkish commandos against PKK bases in Iraqi Kurdistan.

Foreign ministry spokesman Namik Tan said the Iraqi ambassador was told the border reinforcements were part of measures enhanced every year with the arrival of spring, when the snows melt and make passage through the mountains along the border easier for the rebels.

"The presence and activities of the PKK in Iraq makes these measures compulsory," he said. "We conveyed again to the ambassador our view that the presence and activities of the PKK in Iraq must be terminated."

Rice pledged US support against the PKK on Thursday, but opposed cross-border operations, saying they could complicate efforts to restore stability in Iraq.

She called for the resumption of trilateral meetings between Ankara, Baghdad and Washington to discuss measures against the PKK once the new Iraqi government takes office.

The Kurdish conflict in Turkey has claimed more than 37,000 lives since 1984, when the PKK launched its armed separatist campaign.