Turkish fighter jets have bombed Kurdish rebel targets in northern Iraq, a spokesman for Iraqi Kurdistan's Peshmerga security forces said. Jabar Yawar said the jets bombed an area about 85 kilometers north of Irbil near the border with Turkey on Sunday for about an hour and a half. He said there were no civilian casualties because the area was deserted due to a fear of Turkish attacks. Yawar said he did not know whether any Kurdish rebels had been killed. Prime Minister Recep Tayyip Erdogan referred questions to the General Staff, but military authorities were not immediately available to discuss any military operations Sunday. "We are using our nation's natural right under international law," while keeping within limits of reason, Erdogan said when journalists asked about reports of a fresh cross-border operation, state-run media reported. The US ambassador to Iraq Ryan Crocker said before Sunday's attack that the US acknowledges Turkey's right to defend itself but asked the US ally and NATO member not to endanger Iraq's stability. "At the same time we've also said that we all have a pretty substantial interest in the stability of Iraq and none of us want to see operations pursued in a manner that can threaten basic stability inside Iraq," Crocker said. On Saturday, Turkey staged its third cross-border operation against rebels in neighboring Iraq in less than a week. The pro-Kurdish news agency Firat said the rebels did not suffer any casualties in Saturday's attack. The Kurdistan Workers' Party, or PKK, has fought for autonomy in Turkey's predominantly Kurdish southeast since 1984. The group is considered a terrorist organization by Turkey, the United States and the European Union. After a surge in attacks by the rebels, some of whom are based in northern Iraq, Turkey said it would tolerate no more PKK attacks. The Parliament voted to allow the military to strike rebel hideouts and camps across the Iraqi border. The US and Iraq have asked Turkey to show restraint in its response to the guerrillas, fearing that a large Turkish incursion could destabilize what has been Iraq's most stable area. Turkish forces have shelled across the border periodically, and sometimes have carried out "hot pursuits" - limited raids on the Iraqi side that last only a few hours. In a meeting with Turkish Prime Minister Erdogan on Nov. 5, US President George W. Bush declared the PKK a "common enemy," and promised to share intelligence on the rebel group. Washington has been providing Turkey with intelligence, and a "coordination center" has been set up in Ankara so Turks, Iraqis and Americans can share information. The first confirmed air assault by Turkish forces in Iraq came on Dec. 16, when up to 50 Turkish warplanes entered Iraqi air space and bombed suspected PKK targets, prompting Iraqi officials' to complain that Turkey's actions were a violation of Iraqi sovereignty. Still, they have said they recognize the threat posed by the PKK. The military said Saturday that "hundreds" of Kurdish guerrillas had been killed in that operation and in an incursion into Iraq by Turkish land forces two days later. On Saturday, Turkish jets bombed rebel targets inside Iraq for half an hour, following up by shelling the area from inside Turkish border. It was the third confirmed cross-border operation in less than a week by the Turkish forces.