Military sources in Turkey's southeast told Reuters that two or three warplanes had bombed the Iraqi border region on Wednesday evening after Kurdistan Workers Party (PKK) forces were identified in the area.

The military sources said that they landed on an uncontrolled part of the border, but would not say if the bombs landed inside Iraq. The action was not significant and it was not clear what damage had been caused, the sources said.

A Turkish foreign ministry official declined to confirm the report, which comes after Turkish media reported that F-16 aircraft had attacked PKK positions inside Iraq.

Right to defend

Armed clashes have intensified since April, when the Turkish military sent tens of thousands of extra troops to the southeast to reinforce more than 200,000 soldiers already stationed there.

George Bush told Recep Tayyip Erdogan, the Turkish prime minister, last month that the US wanted to deal more aggressively with cross-border attacks by PKK rebels.

However, diplomats in Ankara say that the government and the armed forces are frustrated at little action on the ground despite mounting casualties in Turkey, which many believe has given the PKK time to regroup.

Several thousand PKK separatist fighters are based in the mountains of northern Iraq and Turkey has insisted that it has the right to conduct cross-border operations should Washington and Baghdad fail to crack down on the fighters.

Iraq has repeatedly warned Turkey not send troops into its territory.

The PKK has denied the reports in a statement: "News that Turkish military forces' F-16 planes bombed south Kurdistan border areas are lies and unfounded."