The remains of two children are among 146 bodies exhumed from a mass grave near the city of Izyum in eastern Ukraine, an official said.
Many of the victims are civilians, some are believed to have been tortured while undergoing violent death, authorities said Monday.
The mass cemetery with 440 graves was found after the city was liberated from Russian control by Ukrainian forces.
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The city was recaptured after a counter-offensive in the Kharkiv region.
Kharkiv governor Oleh Synehubov said two children were among the bodies in Izyum.
“Some of the dead show signs of a violent death,” he said.
“There are bodies with tied hands and traces of torture.”
“The deceased were also found to have explosives, shrapnel and stab wounds,” he added.
Forensic experts wearing white protective suits and rubber gloves spent days painstakingly excavating and identifying the bodies buried in makeshift graves marked with thin wooden crosses.
President Volodymyr Zelenskyy was pictured in the newly recaptured city hoisted his country’s blue-and-yellow flag in a triumphant show last Wednesday.
After the discovery of the cemetery, Zelenskyy’s chief of staff Andriy Yermak called Russia a “killer country” and a “state sponsor of terrorism”.
Kremlin spokesman Dmitry Peskov dismissed Ukraine’s accusations as a “lie”.
In his overnight address to the nation last Thursday, Mr Zelenskyy said: “We want the world to know what is really happening and what the Russian occupation has led to.
“Bucha, Mariupol and now unfortunately Izyum.
Forensic experts carry the body of a person killed in the Russian invasion, according to Ukrainian police, near the village of Vorzel in Bucha
A Ukrainian soldier walks among destroyed Russian tanks in Bucha, on the outskirts of Kiev, in April. Photo: AP
“Russia leaves death everywhere. And it has to be held accountable for that. The world really needs to hold Russia accountable for this war.”
US President Joe Biden previously called Russian leader Vladimir Putin a “war criminal” about civilian killings in Bucha, outside the capital Kiev.
Some were shot in the head with their hands tied behind their backs, according to Ukrainian officials.
But Moscow has categorically denied being responsible for the massacre.
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