Turkish troops have killed 13 Kurdish militants and wounded at least five more in three days of a large operation in southeast Turkey, a senior military officer said on Monday.

The clashes come as the first winter snows settle in the mountains of mainly Kurdish southeast Turkey, a time when clashes between the military and the Kurdistan Workers Party (PKK) traditionally ease off as movement becomes more difficult.

Turkey's deputy Prime Minister Besir Atalay denied media reports of secret negotiations with the PKK to end the 27-year conflict that has killed more than 40,000 people.

Our winter operations will continue, there is not and there will not be, any pause, Atalay said in a television interview. But he said the government was determined to continue to try to undercut the insurgency with democratic reforms.

Some 3,000 troops, backed by strike aircraft and attack helicopters, began the latest operation after identifying a group of around 30 PKK fighters on Goresi Mountain on the border of Elazig and Diyarbakir provinces in southeast Turkey.

After a series of clashes, 13 militants have been killed and at least five wounded, the officer said, adding that the operation was ongoing, but expected to end on Tuesday.

The PKK took up arms to fight for a separate Kurdish state in southeast Turkey in 1984, but has since tempered its demands to wanting greater rights for Kurds.

The United States, the European Union, as well as Turkey, all regard the PKK as a terrorist organisation.

Turkey's ruling AK Party, which emerged from a string of banned Islamist parties, has passed laws granting greater cultural and language rights for the country's Kurds, some 20 percent of the population, and is currently negotiating with Kurdish members of parliament to gain their support for a new constitution which it says will bring greater equality.

(Writing by Jon Hemming; Editing by Giles Elgood)