The city was among the first to be occupied by Russian forces since the war began on 24 February.
More than 400 bodies have been recovered, many of whom died violent deaths, with some showing signs of torture.
“New evidence of the torture used against the people buried [in Izium] has been found. More than ten torture chambers have already been found in the liberated areas of Kharkiv region,” Ukraine president Volodymyr Zelensky said.
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