Ukrainian authorities have exhumed dozens of bodies, including a one-year-old baby, to determine the causes of death following the retreat of Russian troops from two recently-liberated towns in the eastern Donetsk region, according to officials.

“These are local civilians and our defenders, armed forces servicemen,” Donetsk Governor Pavlo Kyrylenko said on Tuesday at a cemetery in Lyman, which was retaken from Russian forces on October 1.

He added that 55 bodies had been exhumed and that preliminary results indicated that the deaths resulted from “explosive and projectile injuries, bullet injuries”.

Ukrainian authorities were cautious in saying whether any of the bodies exhumed Tuesday showed signs of having been executed or subjected to torture, emphasizing that the investigation was still in its early stages.

At a separate site on Tuesday, about 20km (15 miles) to the west in the town of Sviatohirsk, the prosecutor general’s office said law enforcement officers had exhumed 34 bodies, some of which it said showed signs of violence, including gunshot wounds, rib and skull fractures, as well as injuries caused by explosives.

“The burned bodies of two citizens were also found in a car,” it said in the statement. “Their identities are being established.”

Ukrainian authorities have repeatedly accused Russian troops of committing atrocities in occupied territories, a charge Moscow denies.

Last month the bodies of 436 people were exhumed from a burial site in the northeastern town of Izyum after it was liberated. Most appeared to have died violent deaths, local officials said.