Ukrainian President Volodymyr Zelenskyy returned to Ukraine on Saturday bringing home with him five former Azov commanders who had fought in the battle over Mariupol. The Kremlin accused Turkey of violating the prisoner-exchange agreement that was signed last year.

“We are returning home from Türkiye and bringing our heroes home,” Zelenskyy wrote on social media. “Ukrainian soldiers Denys Prokopenko, Svyatoslav Palamar, Serhiy Volynsky, Oleh Khomenko and Denys Shleha. They will finally be with their relatives.” 

The Ukrainian president hugged the servicemen at the Istanbul airport and flew them home with him.

Upon news of the release, Kremlin spokesman Dmitry Peskov said Russia had not been informed and that Turkey had promised to keep the former prisoners on its home soil.

The move “goes against the terms of existing agreements,”Peskov said. “The conditions of return were violated by both the Turkish and Kyiv sides,” he said.

“Nobody informed us about this. According to the terms of the agreement, these persons were supposed to stay on the territory of Türkiye until the end of the conflict,” Peskov said.

Peskov claimed that NATO pressured Turkey to violate the agreement to demonstrate solidarity with the alliance ahead of the this week’s NATO summit in Vilnius.

Russian pro-Kremlin analysts said that Turkish President Recep Tayyip Erdoğan’s decisions first to support Ukraine’s NATO bid and then let the military commanders return to Ukraine were “an insult to Russia.”

“This shows clearly that Russia finds itself in a situation where violating agreements with Russia has become the norm,” Sergei Markov, a former Kremlin adviser, wrote on Telegram. “Because Russia does not respond. Out of humility or humanism. It needs to respond. Respond in such a way that will instill fear,” Markov said.

The five commanders — from the 12th Ukrainian National Guard, its separate Azov regiment and the 36th Separate Marine Brigade of the Ukrainian army — were ordered to surrender to Russian forces in May 2022 after holding out for more than two months defending the the Azovstal steel plant in Mariupol.

The Azovstal commanders, along with 2,500 Ukrainian servicemen, were taken into Russian captivity. The Kremlin labeled all of them Nazis, with some Russian officials even saying the Ukrainian soldiers deserved execution by hanging.

In September 2022, Ukraine managed to release of some 215 Azovstal fighters, including the five commanders, in a prisoner swap, one of the largest in the history of the Russian invasion of Ukraine, brokered by Turkkey’s Erdogan.

In return, Russia got 55 of its own soldiers, officers and pilots, as well as Ukrainian politician Viktor Medvedchuk, once considered a close ally of Russian President Vladimir Putin. The Kremlin also got guarantees that all five commanders would remain in Turkey until the end of the war.

Last summer, the Supreme Court of Russia recognized the Ukrainian regiment “Azov” as a “terrorist organization” in Russia.

Veronika Melkozerova contributed to this report.