Escalating tensions between Turkey and Iraq are threatening to further disrupt the long-awaited campaign against the Islamic State in Mosul, as Iraqi Prime Minister Haider al-Abadi warned of “regional conflict” over the continued presence of Turkish troops in Northern Iraq.

Turkey’s parliament voted Oct. 1 to extend the mandate of thousands of Turkish troops inside Iraq and Syria, sparking an outcry in Baghdad. “We have asked the Turkish side more than once not to intervene in Iraqi matters and I fear the Turkish adventure could turn into a regional war,” Abadi told Iraqi state television.

Ankara insists that its troops are deployed in its former Ottoman dominions to combat “terrorist organizations,” meaning the Islamic State and the Kurdistan Workers Party (PKK). There is mounting concern over a possible confrontation between Turkish forces and the Iraqi Popular Mobilization Units (PMU), the predominantly Shiite paramilitary militias that are likely to seek credit for liberating Mosul.

Turkish Prime Minister Binali Yildirim told the Turkish Parliament on Oct. 4 that the operation to wrest Mosul from IS could spark Shiite-Sunni fighting if the city were placed under Shiite control. Turkey’s president, Recep Tayyip Erdogan, had earlier inflamed Iraqi sensibilities when he told an Emirati news channel that once Mosul, the capital of Ninevah province, is liberated, “only Sunni Arabs, Turkomens, and Sunni Kurds” should be permitted to remain in the city.