Widespread blackouts have affected large areas of the country where Kiev's forces have been making gains in a lightning counter-offensive.
President Volodymyr Zelenskyy has said Russia is responsible for sweeping electricity cuts across east Ukraine, accusing Moscow of hitting civilian infrastructure.
Widespread blackouts affected large areas of the country on Sunday where Kiev's forces have been making gains in a lightning counter-offensive.
"A total blackout in the Kharkiv and Donetsk regions, a partial one in the Zaporizhzhia, Dnipropetrovsk and Sumy regions," Zelenskyy said in a statement on social media, blaming "Russian terrorists".
"No military facilities," he added. "The goal is to deprive people of light and heat."
There was no immediate reaction from Moscow, which denies deliberately hitting civilian infrastructure.
The regional governor of the Kharkiv region, where Ukrainian troops have reported the largest gains, said Russian forces had "struck critical infrastructure" across the region and its main city, also called Kharkiv.
"There is no electricity or water supply in several settlements. Emergency services are working to control fires at the sites that were hit," Oleg Synegubov said in a statement on social media.
Ukrainian officials said Russia hit Kharkiv TEC-5, the country's second-biggest heat and power plant.
Kharkiv Mayor Igor Terekhov called the power outage “revenge by the Russian aggressor for the successes of our army at the front, in particular, in the Kharkiv region”.
Later in the evening, some power had been restored.
The head of the Dnipropetrovsk region, Dmytro Reznichenko, also said Russian forces were responsible for blackouts across his region.
"Several cities and communities in the Dnipropetrovsk region are without electricity. The Russians hit energy infrastructure. They cannot accept defeat on the battlefield," he said in a statement online.
The head of the eastern Sumy region said the cuts to electricity and water supplies had impacted at least 135 towns and villages.
READ MORE:Ukraine counter-offensive reclaims ‘3,000 square km’ from Russian forces
Lyman, the city in the Donetsk region, is still waiting for our flag, and it's inevitable, Ukraine always comes back – Ukrainian President Zelenskyy pic.twitter.com/a9Cm7VkMvo
Kharkiv counter-offensive
Kiev forces have clawed back Russia-occupied areas in the Kharkiv region this month, forcing Moscow to withdraw its troops to prevent them from being surrounded.
As the conflict marked its 200th day on Sunday, Ukraine's military chief Gen. Valerii Zaluzhnyy said his forces had recaptured about 3,000 square kilometres (1,160 square miles) since the counter-offensive began in early September.
He said Ukrainian troops are only 50 kilometres (about 30 miles) from the Russian border.
Meanwhile, the Ukrainian General Staff said Russian forces had left several settlements in the Kherson region as Ukrainian forces pressed the counter-offensive. It did not identify them.
An official with the Russian-backed administration in the city of Kherson, Kirill Stremousov, said on social media that the city was safe and asked everyone to stay calm.
The Russian pullback marked the biggest battlefield success for Ukrainian forces since they thwarted a Russian attempt to seize Kiev near the start of the conflict.
The Kharkiv campaign came as a surprise for Moscow, which had relocated many of its troops from the region to the south in expectation of a counter-offensive there.
READ MORE:Ukraine announces battlefield gains as Russia pulls back from Kharkiv areas
[embed]https://www.youtube.com/watch?v=nFi00eNI3sw[/embed]
Source: TRTWorld and agencies