The Kurdistan Workers’ Party (PKK) has captured four Turkish intelligence operatives in Sulaimaniya after they attempted to arrest or assassinate a top leader of the Kurdish guerrilla group. The incident is putting an acute strain on relations between Iraqi Kurds and the Turkish government at a critical moment. Ankara has already expressed opposition to a Kurdistan Regional Government (KRG) independence referendum scheduled for Sept. 25, largely for fear that it would bolster Kurdish separatists like the PKK in Turkey.