Two Britons and a Moroccan received the death sentence on Thursday from a court in the self-proclaimed Donetsk People’s Republic (DPR), one of Russia’s proxies in eastern Ukraine, Russian news agencies reported.

They were brought to trial after a Ukrainian court sentenced a Russian soldier to life in prison last month for killing an unarmed civilian in Ukraine.

Kyiv said Thursday’s court ruling had no authority, that the fighters were members of the Ukrainian armed forces and that they were subject to Geneva Convention protections.

Vadym Denysenko, an Interior Ministry adviser, said on Friday Ukraine would coordinate its position on the sentences with Britain, the United States and the European Union.

“The trial of the foreigners raises the stakes in the Russian Federation’s negotiation process. They are using them as hostages to put pressure on the world over the negotiation process,” he told national television.

Peace talks between Ukraine and Russia are frozen. Russia has accused Ukraine of blocking talks, but Kyiv says Moscow is to blame.

In a separate negotiating process, Turkey is leading attempts to arrange safe passage for grain stuck in Ukrainian Black Sea ports blockaded by Russia.

Russia did not immediately comment on Denysenko’s remarks.

The two Britons and Moroccan were found guilty of “mercenary activities and committing actions aimed at seizing power and overthrowing the constitutional order” of the self-proclaimed DPR.

(Reporting by Natalia Zinets, Editing by Timothy Heritage)