Ukrainian forces have liberated the town of Luhansk region, a military official said

The victory of Ukrainian forces in the newly liberated Kupiansk has little rest. Russian shells still pound its cobbled streets and stain the sky with plumes of black smoke.

Major damage is seen in almost all buildings. A huge poster with an image of a waving Russian flag stands near the bridge over the Oskil River in the center of the city, proclaiming “We are one nation with Russia!”

For now, the Ukrainian army has chased Russian forces off the bridge and appears to be building some strength along the eastern bank of the river towards Luhansk, the main separatist territory controlled by Moscow. CNN saw Ukrainian infantry returning on foot from the east.

Yet within this city, one of several in the liberated eastern Kharkiv region, there are signs of a hellish occupation. A former police building was used by the Russians as a sprawling detention center that at one point housed 400 prisoners in its cramped, dark cells, eight to nine prisoners per cell, Ukrainian officials told CNN. A vivid mural of a Russian soldier with a “Z” on his arm next to an elderly woman waving the flag of the former Soviet empire is still painted on one wall.

As the authorities continue to investigate and clear liberated villages in the Kharkiv region, they are finding more and more evidence of detention centers and cells used for torture.

Ukrainian President Volodymyr Zelensky said on Saturday that “more than 10 torture chambers” used by the occupying forces had been found in the area. “As the occupiers fled, they also threw away the torture devices,” he said.

CNN has reached out to the Russian government for comment, but has not heard back.

Kupiansk may have been recently liberated, but the city is a ghost town of destruction and ruins.

The very few remaining natives are gathered in the bare native bark.

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