KYIV: Russia attacked power stations and other infrastructure, causing widespread outages across Ukraine as Kyiv's forces pressed a swift counteroffensive that has driven Moscow's troops from swaths of territory it had occupied in the northeast.
The bombardment on Sunday ignited a massive fire at a power station on Kharkiv's western outskirts and killed at least one person.
President Volodymyr Zelenskyy denounced the "deliberate and cynical missile strikes" against civilian targets as acts of terrorism.
Ukraine's second-largest city of Kharkiv appeared to be without power Sunday night.
Cars drove through darkened streets, and the few pedestrians used flashlights or mobile phones to light their way.
Separately, the Zaporizhzhia Nuclear Power Plant in the Russia-occupied south completely shut down in a bid to prevent a radiation disaster as fighting raged nearby.
Kyiv's action in recent days to reclaim Russia-occupied areas in the Kharkiv region forced Moscow to withdraw its troops to prevent them from being surrounded, leaving behind significant numbers of weapons and munitions in a hasty flight as the war marked its 200th day on Sunday.
Ukraine's military chief, Gen. Valerii Zaluzhnyy, said its forces had recaptured about 3,000 square kilometers (1,160 square miles) since the counteroffensive began in early September.
He said Ukrainian troops are only 50 kilometers (about 30 miles) from the Russian border.
One battalion shared a video of Ukrainian forces in front of a municipal building in Hoptivka, a village just over a mile from the border and about 19 kilometers (12 miles) north of Kharkiv.
Kharkiv Gov. Oleh Syniehubov said Ukrainian troops have reclaimed control of more than 40 settlements in the region.
In Sunday night's missile attacks by Russia, the Kharkiv and Donetsk regions seemed to bear the brunt.
Dnipropetrovsk, Zaporizhzhia and Sumy had only partially lost power, Zelenskyy said.
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."
Ukrainian officials said Russia hit Kharkiv TEC-5, the country's second-biggest heat and power plant, and Zelenskyy posted video of the Kharkiv power plant on fire.
"Russian terrorists remain terrorists and attack critical infrastructure. No military facilities, only the goal of leaving people without light and heat," he tweeted, But Zelenskyy remained defiant despite the attacks.
Addressing Russia, he added: "Do you still think you can intimidate, break us, force us to make concessions? Cold, hunger, darkness and thirst for us are not as scary and deadly as your `friendship and brotherhood.' But history will put everything in place. And we will be with gas, lights, water and food, and WITHOUT you!" Later in the evening, some power had been restored in some regions.
None of the outages were believed to be related to the shutdown of the reactors at the Zaporizhzhia plant.
While most attention focused on the counteroffensive, Ukraine's nuclear energy operator said the Zaporizhzhia nuclear power plant, Europe's largest, was reconnected to Ukraine's electricity grid, allowing engineers to shut down its last operational reactor to safeguard it amid the fighting.
The plant, one of the 10 biggest atomic power stations in the world, has been occupied by Russian forces since the early days of the war.
Ukraine and Russia have traded blame for shelling around it.
Since a Sept.5 fire caused by shelling knocked the plant off transmission lines, the reactor was powering crucial safety equipment in so-called "island mode" ,an unreliable regime that left the plant increasingly vulnerable to a potential nuclear accident.
The International Atomic Energy Agency, the U.N. nuclear watchdog that has two experts at the site, welcomed the restoration of external power.
But IAEA Director-General Rafael Grossi said he is "gravely concerned about the situation at the plant, which remains in danger as long as any shelling continues."
He said talks have begun on establishing a safety and security zone around it.
In a call Sunday with Russian President Vladimir Putin, French President Emmanuel Macron urged the withdrawal of Russian troops and weaponry from the plant in line with IAEA recommendations.
The pullback of Moscow's forces in recent days marked the biggest battlefield success for Ukrainian forces since they thwarted a Russian attempt to seize Kyiv near the start of the war.
The Kharkiv campaign seemed to take Moscow by surprise; it had relocated many of its troops from the region to the south in expectation of a counteroffensive there.
Ukrainian troops on Sunday successfully pressed their swift counteroffensive in the northeastern part of the country, even as a nuclear power plant in the Russia-occupied south completely shut down in a bid to prevent a radiation disaster as fighting raged nearby.
Kyiv's action to reclaim Russia-occupied areas in the Kharkiv region forced Moscow to withdraw its troops to prevent them from being surrounded, leaving behind significant numbers of weapons and munitions in a hasty retreat as the war marked its 200th day on Sunday.
A jubilant Ukrainian President Volodymyr Zelenskyy mocked the Russians in a video address Saturday night, saying, "the Russian army in these days is demonstrating the best that it can do, showing its back."
He posted a video of Ukrainian soldiers hoisting the national flag over Chkalovske, another town reclaimed in the counter-offensive.
Yuriy Kochevenko, of the 95th brigade of the Armed Forces of Ukraine, tweeted a video from what appeared to be the city centre of Izyum.
The city was considered an important command and supply hub for Russia's northern front.
"Everything around is destroyed, but we will restore everything. Izyum was, is, and will be Ukraine," Kochevenko said in his video, showing the empty central square and destroyed buildings.
While most attention was focused on the counteroffensive, Ukraine's nuclear energy operator said the Zaporizhzhia nuclear power plant, Europe's largest, was reconnected to Ukraine's electricity grid, allowing engineers to shut down its last operational reactor to safeguard the plant amid the fighting.
The plant, one of the 10 biggest atomic power stations in the world, has been occupied by Russian forces since the early days of the war.
Ukraine and Russia have traded blame for shelling around it.
Kharkiv Gov. Oleh Syniehubov said Ukrainian troops have reclaimed control of more than 40 settlements in the region, noting he couldn't give a precise number because the operation is still unfolding.
Defense Minister Anna Malyar said Ukrainian forces are firing shells containing propaganda into areas where they seek to advance.
"One of the ways of informational work with the enemy in areas where there is no Internet is launching propaganda shells," she wrote on Facebook.
"Before moving forward, our defenders say hello to the Russian invaders and give them the last opportunity to surrender. Otherwise, only death awaits them on Ukrainian soil."
The Ukrainian General Staff said Russian forces had also left several settlements in the Kherson region as Ukrainian forces pressed the counteroffensive.
It did not identify the towns.
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 the capital, Kyiv, near the start of the war.
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 counteroffensive there.
In an awkward attempt to save face, the Russian Defence Ministry said Saturday the troops' withdrawal from Izyum and other areas was intended to strengthen Moscow's forces in the neighbouring Donetsk region to the south.
The explanation sounded similar how Russia justified its pulling back from Kyiv earlier this year.
Igor Strelkov, who led Russia-backed forces when the separatist conflict in the Donbas erupted in 2014, mocked the Russian Defense Ministry's explanation of the retreat, suggesting that handing over Russia's own territory near the border was a "contribution to a Ukrainian settlement."
The retreat drew an angry response from Russian military bloggers and nationalist commentators, who bemoaned it as a major defeat and urged the Kremlin to step up its war efforts.
Many criticised Russian authorities for continuing with fireworks and other lavish festivities in Moscow that marked a city holiday on Saturday despite the debacle in Ukraine.
Putin attended the opening of a huge Ferris wheel in a Moscow park on Saturday, and inaugurated a new transport link and a sports arena.
The action underlined the Kremlin's narrative that the war it calls a special military operation" was going according to plan without affecting Russians' everyday lives.
Pro-Kremlin political analyst Sergei Markov criticized the Moscow festivities as a grave mistake.
"The fireworks in Moscow on a tragic day of Russia's military defeat will have extremely serious political consequences," Markov wrote on his messaging app channel.
"Authorities mustn't celebrate when people are mourning."
In a sign of a potential rift in the Russian leadership, Ramzan Kadyrov, the Kremlin-backed head of Chechnya, said the retreat resulted from blunders by the Russian brass.
"They have made mistakes and I think they will draw the necessary conclusions," Kadyrov said.
"If they don't make changes in the strategy of conducting the special military operation in the next day or two, I will be forced to contact the leadership of the Defense Ministry and the leadership of the country to explain the real situation on the ground."
Despite Ukraine's gains, U.S. Secretary of State Antony Blinken and the head of NATO warned Friday the war would likely drag on for months, urging the West to keep supporting Ukraine through what could be a difficult winter.
Sen. Tim Kaine, a Virginia Democrat and member of the Senate Foreign Relations Committee, called Ukrainian advances very encouraging.
"I'm proud that the U.S. and our allies have locked arms to support the Ukrainian people in this fight," Kaine said in a statement to The Associated Press.
"We and our allies must keep standing with Ukraine. Putin needs to recognise that the only way out is to end his failed war."
Through the debris-strewn rooms of the bomb-blasted house, the incessant ringing of a phone punctuates the crunch of broken glass splintering underfoot as police lay out a body bag.
But the call will never be answered.
The phone's owner crouches lifeless on the floor of his home, in a front room where the explosion from a missile, one of several to hit this eastern Ukrainian town, found him.
The missiles that rained down on Pokrovsk Saturday night and into the early hours of Sunday were part of a barrage of attacks on towns in eastern Ukraine's Donetsk region that left at least 10 people dead Saturday, according to Donetsk governor Pavlo Kyrylenko.
They came as Ukraine pressed forward with a counteroffensive just to the north in the Kharkiv region, pushing Russian forces into a retreat from key areas.
Six of the dead were in Pokrovsk, mayor Ruslan Trebushkin said in a message posted on Telegram.
The industrial town about 40 kilometers from the front line had been hit twice before by missiles, in May and July, but never before by so many in one night.
A flash illuminated the night sky as a detonation sounded out across the town in the second of six explosions.
An ambulance raced through the darkened streets, and flames rose from a fire triggered by the missile strikes.
At least three of those who died were killed when one of the missiles struck between a row of small houses and nearby train tracks, collapsing part of a nearby abandoned building, leaving one home burnt to the ground and severely damaging several more.
Oleksandr Zaitsev, 67, stood quietly outside his friend's house as the police arrived.
His friend's wife had been calling her husband nonstop since the strike, he said, but nobody was picking up.
The house's windows were shattered, the walls were pockmarked from shrapnel, and the front door blown off its hinges.
Inside, the police gently rolled Zaitsev's friend into a black body bag.
Next door, Yevhenia Butkova, 47, stood stunned in the center of her living room, trying to calm her two agitated pet dogs.
Blood stained the sofa where she and her husband had been watching television when the first missile struck.
On Sunday morning, he was recovering in a hospital after doctors removed shards of glass from his wounds, she said.
Chunks of debris from the ceiling littered the floor throughout the house, whose entrance was reduced to a jumble of splintered wood, plaster, glass and brick.
One of the plywood boards the couple had put over their windows for protection had been blown clean across the garden.
But a combination of that and the plastic they had put over the glass probably saved their lives, Butkova said.
"It was all quiet in Pokrovsk, this was very unexpected," she said.
"It was horrible."
Further down the row of single-story houses, an elderly couple swept rubble and glass from their small porch, dried blood still streaking their faces.
Mariia Trutko, 85, and her husband Oleksii Maksymenko, 75, had been sleeping when they were jolted awake by the blast.
"I can't hear anything without my hearing aid, and then it hit so hard that I heard," said Maksymenko, a retired coal miner.
"Everything fle. I started bleeding, so we got up to see what that was, and then there was another one: boom! Their bed was littered with jagged shards of glass and plaster from the roof that covered them both," Trutko said.
A large, square piece of glass lay on the pillow, and spots of blood stained the floor.
"Oh my God, we could never imagine going through something like this at this old age," Maksymenko said.