Turkish helicopters ferried more troops to the border with Iraq on Friday as diplomatic efforts got underway in Ankara to avert a major offensive against Kurdish guerrillas based in northern Iraq.

State-run Anatolian news agency said Cobra helicopters and fighter jets had also pounded PKK shelters discovered after reconnaissance missions along the border and inside Turkey, which has NATO's second biggest army.

Turkey has massed up to 100,000 troops along the mountainous border before a possible cross-border operation to crush about 3,000 guerrillas of the outlawed Kurdistan Workers Party (PKK) who launch deadly attacks into Turkey from northern Iraq.

Iraqi, Turkish and U.S. diplomats have stepped up efforts to avert a large-scale Turkish incursion but Turkey's prime minister and president have repeatedly said their country would not tolerate any more PKK attacks from Iraq.

"We are moving more troops from other provinces to Sirnak province," a military source, who declined to be named, told Reuters in southeast Turkey. Turkey's military has boosted troop levels mainly in Hakkari and Sirnak provinces bordering Iraq.

Anatolian news agency said that helicopters, also carrying military equipment, took off from Yusekova town in Hakkari province and headed for Daglica region near the Iraq border.

An Iraqi delegation began talks with Turkish civilian and military officials on Friday in Ankara.

ANKARA TALKS

Iraqi Defense Minister General Abdel Qader Jassim, heading the delegation, told reporters on arrival on Thursday that they had come with concrete proposals.

He declined to give further details.

"For the Iraqis those proposals may be concrete and strong but for us some of the proposals may be weak because our perspective differs, so we are now having internal consultations," a Turkish official, who declined to be named, told Reuters, adding that these talks were ongoing parallel to bilateral talks.

Ankara, which wants U.S. and Iraqi authorities to shut down PKK camps and hand over rebel leaders, is skeptical about Baghdad's ability to crack down on the PKK in northern Iraq, a mainly Kurdish region where central government has little clout.

Iraqi Kurdish leader Masoud Barzani has infuriated Turkey by refusing to act against the PKK. He has said his peshmerga fighters will resist any Turkish incursion.

The United States is keen to avert a large-scale Turkish offensive in northern Iraq, fearing it would destabilize not only the most peaceful part of that country but potentially also the region as a whole.

"... I hope that peaceful actions can be taken and not military actions which would only create very strong instability," U.N. Secretary-General Ban Ki-moon told Italian newspaper La Stampa in comments published on Friday.

Public pressure on Turkish authorities to act has grown since rebels killed some 40 soldiers over the last month. The PKK, branded a terrorist organization by the United States and the European Union as well as Turkey, has said it captured eight soldiers.

Secretary of State Condoleezza Rice is due to visit Turkey on November 2 and 3, while Erdogan is expected to meet President George W. Bush in Washington on November 5.

(Additional reporting by Evren Mesci in Ankara)

Iraq