Yevhenii Matvieiev, the mayor of the occupied Dniprorudne town, was tortured to death in Russian captivity, Zaporizhzhia Oblast Governor Ivan Fedorov said on his Telegram channel on Dec. 4.

"People are the most valuable thing we are losing in this merciless war waged by the terrorist country of Russia," the governor said.

Russian forces occupied the southeastern town of Dniprorudne in Zaporizhzhia Oblast during the early days of the war, taking the mayor to captivity and submitting him to torture, Fedorov said.

Matvieiev spent two years and eight months in captivity before dying. His body was returned to Ukraine during the latest exchange.

"Yevhenii was a true patriot, not indifferent to the fate of his country and his community. He always worked with people and for people, listened, and helped everyone who needed it," Fedorov said.

"During the occupation, he did not leave the town or the people, did everything to ensure the (continuation of the) life of the community, constantly informed the population about the course of events and supported them."

Russia's occupation has been accompanied by widespread human rights abuses, including torture and murder of civilians. Mass kidnappings were not uncommon in Russian-occupied territories in the early days of the war and reached its apogee with the abduction of 20,000 children.