Turkish warplanes bombed an area of Iraq near the border with Turkey on Tuesday, in the latest of a string of air and ground strikes on Kurdish separatists, Iraqi and Turkish sources said.
A Turkish military source said warplanes launched the limited strike after spotting Kurdistan Workers Party (PKK) guerrillas during a reconnaissance flight. He said the strike was smaller than others in recent weeks.
Colonel Hussein Tamar, director of Iraq's border guard command in the northern Kurdish province of Dahuk, said villages near the border were hit but nobody was hurt.
The area was depopulated because residents had fled earlier attacks this month, he said.
Turkey has repeatedly bombed areas of northern Iraq in pursuit of PKK rebels over the past few weeks. Ground troops have also made occasional cross-border raids, although a large-scale assault is seen as unlikely, especially in winter.
The Turkish general staff said on Tuesday that a strike it had launched on Dec 16 had killed more than 150 PKK fighters.
Prime Minister Tayyip Erdogan defended the strikes, which he said targeted only PKK separatist guerrillas.
"No matter who says what, we are using and continue to use air and land operations within the framework of authority granted by international law," he said in a speech to his political party, without referring directly to Tuesday's strike.
"Nobody can object to that if Turkey is responding to attacks against its unity, citizens and soldiers." The Turkish cross-border strikes have forced Washington to walk a careful line between the interests of two close allies.
US military spokesman Rear Admiral Greg Smith said Turkish authorities had informed US forces in advance of plans to fly a reconnaissance mission over Iraq, but US forces were not immediately aware of whether the air craft had opened fire.
Turkey says it has the right to pursue PKK guerrillas after the rebels carried out a string of deadly attacks in Turkey.
US and Iraqi leaders say they support Turkey's right to hit back at the separatists, but want action to be limited in scale and coordinated to avoid destabilising northern Iraq.
Iraq complained earlier this month that Turkish forces had killed a civilian in an air strike. The leader of the semi-autonomous Kurdish region cancelled a meeting with US Secretary of State Condoleezza Rice last week, accusing Washington of condoning Turkish attacks.