Only days after the release of two Greek soldiers held since March 1 after accidentally crossing the border, relations with Turkey turned sour again after Greece’s highest court gave asylum to a Turkish soldier seeking asylum, which could make him eligible to have travel documents.

Suleyman Ozkaynakci, who piloted the helicopter in which he and seven other officers arrived in Greece after fleeing a failed coup against President Recep Tayyip Erdogan in July, 2016 – they denied taking part, was given sanctuary.

He and his colleagues, who had been freed from the maximum 18 months detention, were said to be at a military barracks under riot police guard after a Turkish official warned they could be kidnapped and forcibly returned.

Prime Minister and Radical Left SYRIZA leader Alexis Tsipras opposes asylum for them but said they can’t be returned after the Council of State ruled against extradition, saying their lives could be in danger with Erdogan, who gained near-dictatorial power in snap elections this year, having purged civil society and the military and mulling return of the death penalty.

Erdogan had been furious that Tsipras wouldn’t override the courts and send back the Turkish soldiers and now the Turkish Foreign Ministry and top government officials accusing Greece of violating the Geneva Convention and protecting terrorists.

The Council of State said that there was no evidence linking the serviceman to the coup and to the Islamic organization FETO run by the cleric Fethullah Gulen, who lives in self-exile in Pennsylvania and is accused by Erdogan of being the the coup attempt mastermind.

“This decision not only breaches Greece’s international obligations to combat terrorism, but also constitutes a violation of the provisions of the 1951 Geneva Convention relating to the Status of Refugees,” the Turkish Foreign Ministry said, blasting the court for ignoring an appeal by the Greek state giving him asylum.

But the court had cited the Geneva Convention as one of the reasons against extradition, believing that Ozkaynakci could face persecution in Turkey over political beliefs.

Omer Celik, the spokesman for Turkey’s ruling Justice and Development Party (AKP), tweeted that the Greek court was protecting “coup plotter terrorists,” while Presiential Spokesman Ibrahim Kalin said the “scandalous” decision should be condemned by the European Union.

Later, the shadow foreign minister for the major opposition New Democracy, Giorgos Koumoutsakos, said that, “Mr. Celik and the Turkish side in general must finally grasp that institutions in Greece operate on the basis of fundamental democratic principles. There is no need for Greek-Turkish relations to be poisoned by such unfounded reactions.”

The release of the Greek soldiers, who said the crossed the border unknowingly while on patrol in bad weather had led to a warming in relations and an agreement to put back on the table some mutual sporting and cultural events between the countries and exchange of military cadets.