Ankara: Turkey wound down its major ground offensive against Kurdish PKK rebels inside northern Iraq yesterday, although it declined to confirm an Iraqi minister's statement that it had already withdrawn all its troops.

The NTV news channel said the cross-border incursion, which began late on February 21, had ended at midnight Thursday and troops had begun pulling out.

It broadcast footage showing a convoy of military vehicles carrying several dozen soldiers, entering Turkey from the border town of Cukurca. The CNN Turk news channel, however, quoted an unnamed military source as saying that "only troops who have completed their mission are returning home" - suggesting a rotation rather than a withdrawal.

Turkey sent thousands of soldiers into remote, mountainous northern Iraq to crush rebels of the outlawed Kurdistan Workers' Party (PKK) who use the region as a base for attacks on Turkish territory. Washington feared the incursion could destabilise an area of relative stability in Iraq.

Iraqi Foreign Minister Hoshiyar Zebari said, "All the Turkish troops have withdrawn and gone back to the Turkish side of the international border. We welcome this, we think this is the right thing for Turkey to do."

A Turkish military source, speaking on condition of anonymity, confirmed only that Turkish forces had fully withdrawn from the key Zap valley in northern Iraq, long a major PKK stronghold, and most had already arrived back in Turkey.

Turkey's military General Staff said it would issue a statement later yesterday.

Earlier, a US official in Baghdad said: "We are seeing a limited portion of the troops that had entered Iraq moving back toward Turkey. [It's] too early to call this a withdrawal."

Turkey's political and military leaders have said the operation will continue for as long as necessary but have come under pressure from the United States, their NATO ally, to keep the campaign as short and carefully targeted as possible. On Thursday, US President George W. Bush urged Turkey to end the land offensive swiftly.

Prolonged campaign

Washington, like Ankara and the EU, brands the PKK a terrorist organisation, and has been supplying intelligence to the Turkish military on the PKK in Iraq. But it fears that a prolonged campaign could stoke regional instability.

Turkey's military says it has killed 237 rebels in the eight-day ground offensive and suffered the loss of 24 soldiers. The PKK says it has killed more than 100 Turkish troops but has not given a figure for its own casualties.

During a brief visit to Ankara on Thursday, US Defence Secretary Robert Gates said he had failed to obtain a timetable for a Turkish withdrawal.

It is Turkey's first major incursion into northern Iraq in a decade.

Turkey's government had insisted the ground operation, backed by warplanes, tanks, long-range artillery and attack helicopters, would continue until PKK bases were erased and the rebels no longer posed a threat to Turkey.

Iraqi Kurds, long suspicious of neighbouring Turkey, fear it is seeking to undermine the autonomy of Iraq's oil-rich Kurdistan region. Ankara says it wants only to end terrorism.

The PKK has been fighting for decades for ethnic rights and self-rule in the mainly Kurdish southeast of Turkey.