Turkey sought on Tuesday to allay growing concern about its ground incursion against Kurdish rebels in Iraq amid reports that Turkish commandos were operating as far south as Mount Qandil, the guerrilla headquarters near Iraq's border with Iran. Prime Minister Recep Tayyip Erdogan, however, did not put a time frame on Turkey's military campaign against the rebel Kurdistan Workers' Party, which began last week. He said the operation would end "once its goal has been reached." Turkish officials have said their only target is the rebel group, also known as PKK, and innocent civilians would be spared. But the US-backed, Iraqi government has demanded an immediate withdrawal of Turkish troops and there are fears that Iraqi Kurd security forces could be drawn into the conflict in the event of a protracted incursion. "The cross-border operation is a result of Turkey's right to self-defense," Erdogan said in a weekly address to ruling party lawmakers. "The international community has understood well Turkey's need to fight terrorist elements. Everyone has begun to understand well Turkey's rightful cause."