Kurdish irregular fighters known as peshmergas, aided by US special forces, moved into Kirkuk to quell what they said was a popular uprising following the departure of troops loyal to Iraqi President Saddam Hussein.

Shortly after news broke of Kirkuk's fall, Turkish Foreign Minister Abdullah Gul warned the Kurds about taking any permanent designs on the city, stressing "we will not allow any fait accompli".

Ankara fears that control of local oil resources could embolden Iraqi Kurds to move towards independence, a prospect that could set an example to their restless fellow Kurds across the border in Turkey.

It has repeatedly threatened to intervene militarily if local Kurds are allowed to seize Kirkuk or Mosul, the largest city in northern Iraq.

Kirkuk is historically Kurdish, and Kurds who have held their own northern enclave protected by US and British warplanes since the end of the 1991 Gulkf War see it as their future capital in a federal Iraq.

Hosman Banimarany, military commander of the Patriotic Union of Kurdistan (PUK), one of the two main Kurdish factions governing Iraqi Kurdistan, told AFP that "peshmergas and the Americans entered Kirkuk after the population staged an uprising".

"When the Iraqis finished their withdrawal, the population rose up. There was some small fighting close to the airport. We then entered to stabilize the situation," he told AFP.

A US soldier also said American troops had entered the city to restore stability in Kirkuk following an uprising, but he said peshmergas already in the city had stirred it up.

Banimarany also said the peshmergas, who have been working closely with US special forces harassing Iraqi positions and calling in airstrikes, would stay in Kirkuk to "make our plans for Tikrit," Saddam's stronghold on the road to Baghdad.

He said his forces were in control of the city's oilfields. A US officer assisting the peshmerga advance also confirmed American units had taken up positions around the fields.

Kirkuk is the centre of the country's oil industry and has been one of the key objectives of the three-week-old joint coalition and Kurdish rebel military push in northern Iraq.

In Ankara, Gul told reporters that US Secretary of State Colin Powell had pledged in a telephone conversation to rush reinforcements to Kirkuk to replace Kurdish fighters.

"He said they would send new US forces to Kirkuk in a few hours. They will take out those who have entered," Gul said.

Gul stressed that Turkey would also not allow returning Kurdish refugees to change the demographic make-up of Mosul and Kirkuk.

"We will not permit either armed people or those without arms, who could try to destroy the demography and the structure of these towns," he said.

"We will do what is necessary. Turkey's position is open and clear," he also warned in a separate statement quoted by Anatolia news agency.

The Iraqi Kurds lay claim to both cities, saying they were in the majority there before many were expelled under Saddam Hussein's "Arabisation" policy. As soon as they heard of Kirkuk's fall, thousands of Kurds began pouring into the city, vowing to reclaim their confiscated homes and property.

However Rizgarali Hamgam, named by the Kurds as "governor in exile" of Kirkuk, said Kurdish troops would have to leave the city.

"The peshmergas will never be authorised to remain. They will have to withdraw," Hamgam told AFP, without giving a date.

A US special forces soldier told AFP the Americans, the peshmergas and the population controlled the major part of the city.

In the city centre, groups of heavily-armed peshmergas could be seen in front of the local government buildings.

On the edge of the city, the looting began in earnest, with residents running away with everything they could find, from refrigerators to air conditioning devices from administrative buildings.

Residents pulled down a large statue of Saddam Hussein in the central square and burned a giant portrait of the Iraqi president.

They took several hours to demolish the statue, showing Saddam wearing traditional robes, with sledgehammers and a cable, as they cried "Down with Saddam, Bush, Bush!"

SPACE.WIRE