DIYARBAKIR, Turkey (Reuters) - The Kurdistan regional government in northern Iraq on Tuesday denied media reports that Turkish military helicopters seeking Kurdish rebels had bombed empty villages in the area.

Jamal Abdullah, a spokesman for the semi-autonomous Kurdistan Regional Government, said two Turkish warplanes had dropped flares as they flew over a village near Zakho in northern Iraq near the Turkish border on Monday.

Earlier Turkish television channels CNN Turk and NTV reported, citing Iraqi officials, that Turkish helicopters bombed villages near Zakho but nobody was killed.

The unconfirmed reports came as four Turkish soldiers were killed in a clash with militants of the outlawed Kurdistan Workers Party (PKK) in southeast Turkey near the Iraqi border.

A lieutenant and three privates died in the clash in Sirnak province, where Turkey has massed large numbers of troops in preparation for a possible major incursion into northern Iraq to root out PKK rebels believed hiding there.

They were the first casualties of the conflict on Turkish territory since November 7 when one soldier and three PKK guerrillas were killed in clashes.

An estimated 3,000 rebels use northern Iraq as a base for attacks in Turkey. The PKK took up arms in 1984 with the aim of creating an ethnic homeland in mainly Kurdish southeast Turkey.

Nearly 40,000 people have been killed in the conflict.

Ankara claims the right of self-defence under international law to attack the PKK inside Iraqi territory and is known to have staged limited cross-border operations against the PKK.

Asked in parliament about the report that PKK premises in northern Iraq had been bombed, Turkish Prime Minister Tayyip Erdogan said: "I am not aware (of that)."

After meeting U.S. President George W. Bush last week to discuss the issue, Erdogan said the army would go ahead with an incursion against the militants in Iraq, but did not say when.

The armed forces chief, General Yasar Buyukanit, said last Friday the military was ready and waiting for the government to order the cross-border operation, according to media reports.

The death of the four soldiers in Sirnak province is likely to increase pressure on the government to authorise a cross-border operation, despite logistical difficulties as winter sets in across the rugged mountainous region.

(Reporting by Sherko Raouf in Sulaimaniya, Gareth Jones in Ankara and Daren Butler in Istanbul; Editing by Charles Dick)