Turkey has deported 50 Nigerian students who studied at a Fethullah Gülen-linked university in İstanbul after a diplomatic dispute with the African country broke out over the detention of the students at the airport on Oct. 1.

Earlier on Thursday the Nigerian House of Representatives gave the Turkish government a seven-day ultimatum to release 50 Nigerian students who were detained as part of a government-led crackdown on the faith-based Gülen movement.

On Oct. 1, 50 Nigerian students, mainly from Fatih University, were detained by Turkish police at İstanbul Atatürk Airport for allegedly being students of a “terrorist organization.”

The Turkish government recently shut down Fatih University over alleged links to the Gülen movement, a global civil society movement inspired by the views of US-based Turkish Islamic scholar Fethullah Gülen, who the government accuses of masterminding a failed coup on July 15 in Turkey. The scholar denies any link to the coup.

Immediately after coup attempt, the government also arrested two Nigerian students on charges of alleged ties to the coup. Nigeria is demanding the release of these students as well.

The Turkish ambassador to Nigeria was summoned by the Nigerian foreign ministry and warned of retaliation against Turkish nationals in the country. Nigerian officials told the media that the Turkish government had acted in a retaliatory fashion after they rejected Ankara’s demand to shut down Turkish schools linked with the Gülen movement.

Sola Enikanolaye, a top diplomat in the Nigerian Foreign Ministry, said those schools have not violated any law in Nigeria and that the Nigerian government cannot close them according to international law unless they engaged in wrongdoing.

President Recep Tayyip Erdoğan’s government has launched a global campaign against Gülen-linked schools, so far with no effect as most countries are refusing to heed Ankara’s demand to close them down.