Turkish Cobra attack helicopters fired missiles at positions of the outlawed Kurdish Workers' Party (PKK) on the second day of a massive operation on Cudi Mountain in southeastern province of Sirnak, local media reported on Wednesday.

According to the report, operations continued in southeastern province of Hakkari as well as in Tunceli of eastern Anatolia, which is located far from the border.

The operation in Sirnak came after at least 100 PKK rebels were trapped in the Cudi Mountain area after Turkish armed forces blocked exit routes to northern Iraq on Monday, said the report.

Three soldiers died in the ongoing operation in Sirnak and another one died in Tunceli in a landmine explosion, making the total number of casualties in the past 24 hours to four, while the number of PKK rebels killed in recent operations rose to 17.

Governor's Office in Sirnak said the security forces have arrested five members of the PKK, including university students who were trying to cross border to treat PKK rebels, added the report.

Turkey says it has attempted through all diplomatic channels to force the Iraqi government and the United States to crack down on PKK camps in northern Iraq and now it considers a military operation.

The issue will still be on agenda of the US Secretary of State Condoleezza Rice who is to visit Ankara on Friday.

Prime Minister Recep Tayyip Erdogan is also scheduled to visit Washington on November 5 for a meeting with President George W. Bush, which is widely believed to be vital in determining whether Turkey will launch military incursion into northern Iraq.

Meanwhile, the international conference on Iraq which will be held in Istanbul on November 2-4 is also expected to focus on the border crisis.

Turkey has now massed up to 100,000 troops along the mountainous border with Iraq in preparation for the cross-border operation to crush the about 3,000 strong PKK rebels, which was approved by the Turkish parliament earlier this month.

The PKK took up arms against Turkey in 1984 with the aim of creating an ethnic homeland in the southeast. More than 30,000 people have been killed in the more than two decade conflict.

(Xinhua News Agency November 1, 2007)