As fighting intensified, the army said it had killed another 33 militants of the Kurdistan Workers' Party (PKK), taking the rebel toll, according to Turkish figures, to 112 since the cross-border incursion began Thursday evening.

PKK rebels "are trying to flee southwards in panic," the general staff said in a statement.

"Local Iraqi groups are expected to prevent members of the terrorist organisation -- the biggest enemy of regional peace and stability -- from entering their region and being given protection there," it said.

The warning raised the spectre of a potential confrontation with the autonomous region's Kurdish-run administration, and just hours later Baghdad called for a swift Turkish withdrawal.

A statement issued by the government of Prime Minister Nuri al-Maliki urged Turkey "to withdraw its forces from Iraqi soil as soon possible" and specifically described the operation as "a threat to Iraqi sovereignty."

Previously, Baghdad had appeared to accept Turkey's assertions that the offensive posed no threat to its territorial integrity.

Turkey and the Iraqi Kurds are both US allies, and the likelihood of armed confrontation between the two has been a major cause of concern for Washington as it seeks to avoid a relatively stable area of conflict-torn Iraq being thrown into chaos.

Ankara has long accused the Iraqi Kurds of tolerating and even aiding the PKK by providing them safe haven, weapons and ammunition.

The Turkish army also confirmed that one of its helicopters had been "destroyed," but gave no details of the incident. PKK rebels had claimed shooting down a Turkish attack helicopter Saturday in a border region near the town of Amadiyah.

The army said eight Turkish soldiers were killed Sunday, bringing their losses since Thursday to 15. The PKK claimed it had killed 47.

Earlier Sunday, the United States had also called on Ankara to wrap up its incursion as swiftly as possible.

"The shorter the better," US Defence Secretary Robert Gates said in Canberra.

Gates, who is expected in Ankara next week, suggested Ankara adopt economic and political measures to win over Turkey's sizeable Kurdish community and erode popular support for the rebels.

"Just using the military techniques are not going to be sufficient to solve the problems," he said.

The United States is providing its NATO ally with real-time intelligence on PKK movements.

Explosions and gunfire were heard Sunday in and around Hakurk, a PKK stronghold, some 20 kilometres (12 miles) from the Turkish border and more than a dozen Turkish warplanes were seen flying missions over the area.

The Firat news agency, considered a PKK mouthpiece, reported air raids and fighting in the region of Zap, home to a major PKK base west of Hakurk and said about 5,000 Turkish soldiers and 60 tanks were advancing toward nearby Haftanin, close to the border town of Zaho.

A senior PKK military leader, Bahoz Erdal, called on Kurds across Turkey, especially those living in urban areas, to rise up in response to the offensive.

"If they want to wipe us out, our youths should make life in the cities unbearable," Firat quoted Erdal as saying. "Kurdish youths should unite... and burn hundreds of cars every night".

Erdal also slammed the United States and Iraqi Kurds for helping Turkey.

"US reconnaissance planes are overflying the region. They instantly convey to the Turkish army information about the position of our forces and then Turkish warplanes come and bomb," he said.

He accused Iraqi President Jalal Talabani, also a Kurd, of having "invited" the Turkish army to the Qandil mountains along the Iraqi-Iranian border, where one of the PKK's main bases is located.

Ankara says an estimated 4,000 PKK rebels are holed up in northern Iraq and use the region as a springboard for cross-border attacks as part of their campaign for self-rule in the Kurdish-majority region of southeast Turkey.

The conflict has claimed more than 37,000 lives since the PKK took up arms in 1984.

burs-su/sf