Large-scale blackouts have hit eastern Ukraine after Russian forces shelled a thermal power plant and water supply facilities in the Kharkiv region.
Ukrainian officials said the attacks took place on Sunday, causing widespread outages around the Kharkiv and Donetsk regions.
The mayor of Kharkiv city said the Russians knocked out power in a "revenge" strike as Ukrainians recaptured some territories in eastern Ukraine.
Ukrainian President Volodymyr Zelenskyy denounced Russia in a message posted on social media. He said "Russian terrorists ... attack critical infrastructure."
He went on to say their "goal is to deprive people of light and heat" instead of targeting military facilities.