Iraq’s ban on international flights into the country’s Kurdish region is set to come into force at 6 pm on Friday. This is the Baghdad government’s retaliation after Kurds in Iraq voted in favour of independence in a referendum on September 25, Reuters reported.

Almost all foreign airlines suspended flights to Erbil and Sulaimaniya, obeying a notice from the government, which controls Iraqi air space. Domestic flights are still allowed.

Earlier on Friday, Turkey asked its citizens to leave Iraq’s semi-autonomous Kurdish region before the flights are suspended, The Independent reported. Turkish carriers Turkish Airlines, AtlasGlobal and Pegasus were scheduled to suspend operations.

Ankara also threatened the Kurdish administration with curbs on oil trade. The Turkish administration is facing a three-decade challenge of a separatist insurgency from its own Kurdish minority and fears the development could encourage the community.

The Iraqi government, Turkey and several other regional players consider the result of the referendum a security threat. Ankara said it would stop training Kurdish Peshmerga forces, which it was undertaking as part of its North Atlantic Treaty Organisation’s membership duties. The Peshmerga were fighting the Islamic State in the region.

The United Nations on Thursday had offered to mediate between the Kurds and Baghdad, the Iraqi foreign ministry said.