Turkey closed its airspace to planes flying to and from Sulaymaniyah International Airport in Iraq’s Kurdish region, accusing separatist militants of using the site.

“Infiltration” of the airport by the Kurdistan Workers’ Party, or PKK, is threatening flight safety, Turkey’s Foreign Ministry said in a statement on Wednesday. The closure will run until July 3.

The PKK, which seeks autonomy for Turkish Kurds, is designated a terrorist organization by the European Union and the US. The government of Turkish President Recep Tayyip Erdogan considers it a major threat, and Sweden’s alleged support for the party is one reason his administration is holding out on approving the Nordic country’s bid to join the North Atlantic Treaty Organization.    

Iraq’s semi-autonomous Kurdistan region and the central government in Baghdad agreed on Tuesday to resume oil exports via Turkey after a legal spat, but shipments are yet to begin.