At least four members of the Kurdistan Workers Party, or PKK, were killed in separate Turkish drone strikes in northern <a href="https://www.thenationalnews.com/mena/iraq/" target="_blank">Iraq</a> on Sunday, authorities in the autonomous Kurdistan region have said. The first attack hit a group of fighters near the Sinjar mountain range, a contested northern Iraqi city about 120 kilometres to the west of Mosul. A second attack hit a small airport used for helicopters in the Iraqi Kurdistan province of Sulaymaniyah, which borders Iran. Sources speaking to Reuters claimed as many as six people had been killed in the latter attack, which wounded a number of Kurdish security personnel. The PKK has been waging a deadly insurgency against the Turkish state for four decades and the conflict has repeatedly spilt across the border into northern Iraq. “A senior official from the Kurdistan Workers' Party and three fighters were killed when a Turkish army drone targeted their vehicle in the Jal Mir region on Mount Sinjar,” Iraqi Kurdistan's counter-terrorism services said in a statement. The Turkish army rarely comments on its strikes in Iraq but routinely conducts military operations against PKK rear bases in autonomous Kurdistan as well as Sinjar district. Ankara and its western allies classify the PKK as a terrorist organisation. Sinjar, the heartland of the Yazidi minority, is also home to a local movement affiliated with the PKK called the Sinjar Resistance Units. On Sunday, the units confirmed the death of “three of our comrades” after a drone strike, which they attributed to Turkey, hit their vehicle. Sulaymaniyah, where the helicopter airport is located, is governed by the Patriotic Union of Kurdistan, a Kurdish party with close ties to Iran-backed groups in Baghdad. Ankara has accused local authorities there of harbouring PKK militants. The PUK has long been at loggerheads with the Kurdistan Democratic Party, which holds sway in Erbil, the capital of the Kurdistan Region of Iraq. The KDP, which has built ties with Ankara over the years, also accuses the PUK of sheltering the PKK. In April, a Turkish air strike hit a military facility near Sulaymaniyah International airport, angering Baghdad, although there were no fatalities. Ankara claimed the PUK had been harbouring a Syrian-Kurdish militia leader at the site. Ankara has set up dozens of military bases in Iraqi Kurdistan over the past 25 years to fight against the PKK. At the end of last month, seven PKK members were killed in northern Iraq in two drone strikes that coincided with a visit by Turkey's Foreign Minister Hakan Fidan to Iraq. The federal authorities and the Kurdistan Regional Government have been accused of tolerating Turkey's military activities to preserve their close economic ties, although statements from Baghdad occasionally condemn Turkey's violation of Iraqi sovereignty and the impact of strikes on civilians. Last summer, strikes attributed to Ankara on a tourist resort in northern Iraq killed nine people, mainly holidaymakers from the country's south. Turkey denied any responsibility and accused the PKK of the attack.