Turkish troops were Monday advancing on the Kurdish Workers' Party (PKK) headquarters located in the Qandil Mountains near the Iraqi border with Iran, as Ankara defended the operation saying Turkey had the right to self-defence, according to dpa. Turkish troops had taken control of large areas in the northern Iraq and had penetrated around 25 kilometres from the border, the Dogan news agency reported. Turkish troops were also conducting operations just inside the Turkish border, Dogan reported. PKK camps in the regions of Zap and Cemco Valley had been destroyed over the weekend and now commandos backed by F-16 warplanes were targeting the PKK's Qandil base near the Iraqi border with Iran, Hurriyet newspaper reported. Turkish government spokesman Cemil Cicek on Monday defended the operation, saying that under international law Turkey had the right to self-defence and to stop the PKK from using Iraq as a base from which to attack civilian and military targets in Turkey. "We told the world (of PKK activities in northern Iraq)... and we wanted measures to be taken. Unfortunately, because Turkey's calls over a long period of time were not answered," Cicek told reporters referring to Turkey's repeated requests that US forces in Iraq or Iraqi forces themselves stop the PKK in northern Iraq. "We have said from the beginning that our one and only target is the PKK separatist terrorist organization," Cicek said adding that the Iraqi people were Turkey's friends. Cicek said that Turkish troops would return home as soon as they have succeeded in destroying the PKK's ability to cross into Turkey to carry out attacks. He refused to speculate when exactly that may be.