The anti-rebel operation, backed by helicopter gunships, took place in mountainous terrain near the eastern town of Pulumur, the CNN Turk news channel reported.

The main road between Tunceli and the neighbouring province of Erzurum was closed early in the morning as the crackdown began, the report said.

The military has reported killing more than 60 fighters from the separatist Kurdistan Workers' Party (PKK) in operations since a PKK ambush near the Iraqi border a week ago left 12 soldiers dead.

Amid appeals for patience from Baghdad and Washington, Turkey has threatened to launch military strikes against PKK bases in northern Iraq unless the Iraqi and US governments make good on promises to crack down on the rebels.

A recent flurry of diplomatic activity was set to continue next with with US Secretary of State Condoleezza Rice expected in Ankara on Thursday for talks with government leaders.

She will then attend a multilateral conference on Iraq in Istanbul.

Iraqi Foreign Minister Hoshyar Zebari is also expected at the conference and may hold bilateral talks with his Turkish counterpart Ali Babacan, a Turkish diplomat told AFP.

Babacan, who visited Tehran on Sunday, warned that Turks had "lost their patience" over what Ankara views as the impunity with which the PKK operates out of bases in northern Iraq.

Turkey accuses the Iraqi Kurds of tolerating and even supporting the PKK, which has fought for self-rule in southeast Turkey since 1984 in a conflict that has claimed more than 37,000 lives.

"We can use diplomacy or we can resort to military means... All of these are on the table," Babacan said after talks with Manouchehr Mottaki, his Iranian counterpart.

Mottaki, whose country has its own restive Kurdish minority and is also fighting PKK-linked militants infiltrating from northern Iraq, stopped short of voicing support for a Turkish incursion.

"There are various ways" of curbing the militants, he said. "We hope our cooperation will allow us to solve this as soon as possible."

Turkish Prime Minister Recep Tayyip Erdogan, scheduled to meet US President George W. Bush at the White House on November 5, warned Saturday that international pressure would not stop Ankara from military action.

"We will launch an operation when it will be necessary, without asking for anybody's opinion," Erdogan said.

The army has massed forces and military equipment along the Iraqi frontier and F-16 fighter jets are ready for "orders to strike," Turkish media say.

The threat of Turkish military action has loomed larger since Friday when Ankara dismissed Iraqi proposals on curbing the PKK as unsatisfactory.

Friday's talks were held in a tense atmosphere and saw some harsh exchanges, a Turkish diplomat said.

When Babacan pressed for the closure of PKK camps, the Iraqi officials argued that the rebel bases were in remote rugged mountains that are difficult to access.

Babacan responded bluntly that "if journalists are able to find the camps then you can certainly find them too," the diplomat said.

The foreign media has recently run several interviews with PKK militants from their bases in northern Iraq. The rebels have also held press conferences in the past.

Beril Dedeoglu, an international relations expert, said Turkey would seek to pressure Rice into agreeing to a joint Turkish-US operation against the PKK in northern Iraq, but was unlikely to receive more than a promise for intelligence assistance.

The crisis has put Washington in an awkward position between two allies -- NATO ally Turkey and the Iraqi Kurds, who run northern Iraq but are reluctant to confront their ethnic brethren from the PKK.