HELSINKI– Prosecutors in Finland brought charges Thursday over alleged war crimes committed in 2014 by a fighter who fought against Ukrainian forces in a Russian-backed separatist region of Ukraine.

The National Prosecutor’s Office did not identify the suspect when it announced the five charges in a statement Thursday, but Finnish media identified him as Russian national Yan Petrovsky, who had been living in Finland under the alias Voislav Torden. The suspect has denied involvement in the crimes.

“The charges relate to the suspect’s activities in a unit called Rusich, which has fought on the side of the Russian-backed separatist Luhansk region against Ukraine,” Finnish prosecutors said.

Finnish media have said Petrovsky was arrested in July 2023 at Helsinki airport while en route to Nice, southern France, with his family. They said Petrovsky had managed to enter Finland despite an EU-wide entry ban with the help of a new identity and his wife’s student status in the Nordic country.

The suspect is “accused of having participated, as deputy commander of the unit, in acts violating the laws of war, in which he and soldiers of the unit killed a total of 22 Ukrainian soldiers and seriously injured four,” prosecutors said.

They added that the suspect is accused of “acts contrary to the laws of war in relation to the conduct of war and the treatment of wounded and dead enemy soldiers.”

Finland’s Supreme Court previously ruled that Petrovsky cannot be extradited to Ukraine, where he faces an arrest warrant, due to the risk of inhumane prison conditions there. Finnish prosecutors said Thursday that the Nordic country has an obligation to prosecute him.

Prosecutors said more information would be made public once the case is brought before the Helsinki District Court, unless the court decides otherwise. No trial date was immediately announced.

The investigation into the suspect, who previously resided in Norway, was conducted by Finland’s National Bureau of Investigation (NBI), and the police agency said earlier this month that it had exchanged information with Ukrainian officials and Europeans, as well as with the International Criminal Court.

Petrovsky has been on the European Union’s sanctions list against Russia for allegedly being a founding member of the far-right paramilitary group Rusich, suspected of terrorist crimes in Ukraine and linked to the Russian mercenary Wagner Group.

In March 2014, Russia annexed the Crimean peninsula in Ukraine. Moscow-backed separatist forces then began an uprising in Ukraine’s eastern region known as Donbas, which turned into a long-running conflict that left thousands dead.

In February 2022, Russian President Vladimir Putin launched his war against Ukraine that continues to this day, with tens of thousands dead on both sides.