Iraq's decision comes despite a conditional ceasefire offer from the rebel group effective Thursday, but follows a warning from Ankara that it would intervene militarily in northern Iraq to root out PKK camps.

"The PKK continues to engage in illegal activities in Iraq and may have offices under various names," government spokesman Ali al-Dabbagh told reporters.

"So for this reason and others, the Iraqi government has decided to close all its offices," he said.

PKK fighters have been active in the Kurdish autonomous region in northern Iraq where Turkey charges they operate rear bases.

Dabbagh said a desire to maintain good relations with Ankara had been a major factor in the decision to close down the movement's offices.

Faik Mohammed Kolbi, an Iraqi Kurdish politician allied to the PKK told AFP earlier Tuesday that there had been heavy pressure on the Kurdish regional government in Iraq from the Turks "to limit its activies and close its offices".

Kolbi, the leader of the Kurdistan Workers' Solution, was arrested two weeks ago and then released six days later.

At the time, supporters said Kolbi's detention was a sop to Turkey from Iraqi authorities eager to show that they are serious in their crackdown.

Ankara, for its part, said Iraq had promised support to fight the PKK at a regional security meeting that ended Tuesday in Jeddah.

Interior Minister Abdulkadir Aksu said he discussed the issue of the PKK with his Iraqi counterpart Jawad Bolani at the meeting.

"I had the opportunity to see that he is determined on the issue of fighting terrorism," Aksu said in a statement.

"My Iraqi counterpart confirmed that they are ready to give all the support they can to our struggle against PKK terrorism."

The PKK, blacklisted as a terrorist organisation by Turkey, the European Union and the United States, has fought for self-rule in mainly Kurdish southeastern Turkey since 1984 in a bloody conflict that has claimed more than 37,000 lives.

Iraq's crackdown comes even as the group proposed a conditional ceasefire starting Thursday.

The ceasefire offer came after repeated requests from the northern Iraqi adminstration of Kurdistan and the US State Department, the group's second-in-command, Murat Karayilan, told AFP.

"We are ready for a ceasefire on September 21 coinciding with World Peace Day," he said.

"Turkey should be ready to respond and flexible in this regard."

Ankara had last month threatened to intervene militarily at the Iraqi border against PKK camps if Baghdad and Washington failed to rein in the rebel group.

Thousands of PKK members have settled in northern Iraq's Kurdistan region since 1999, when the group declared a ceasefire after the arrest of their chief, Abdullah Ocalan, who is serving a life prison sentence.

That ceasefire was broken in June 2004.

Kurdish leader Massud Barzani's recent decision to ban the Iraqi national flag and hoist their own standard had also unnerved Turkey, fearing the emergence of a de facto Kurdish statelet on its doorstep.

Ankara is leery about any moves towards independence across the border that might encourage Kurdish nationalists at home.

Barzani banned the Iraqi flag saying it represented the former regime of Saddam Hussein.