Minnesota Governor Tim Walz said a 57-year-old suspect was arrested on Sunday in the killing of a Democratic state lawmaker and her husband while posing as a police officer.

The prisoners of war (POWs) were released as part of a prisoner exchange with Russia agreed upon during recent peace talks in Istanbul, the Coordination Headquarters for the Treatment of the POWs said.

Ukraine alleged Monday that Russia mixed bodies of its own dead soldiers among the Ukrainian military dead that have been returned, and that more than a million Russians have been killed since conflict began.