Russia rained down scores of missiles on Ukraine's power grid on Friday, killing at least three people, damaging nine energy facilities and forcing Kyiv to introduce emergency blackouts across the country as winter bites.
Many people headed for shelters during the morning rush hour to take cover from the latest big attack on vital infrastructure since October, which a Kyiv official described as one of the largest missile barrages since Russia invaded in February.
The mayor of Kharkiv, Ukraine's second largest city, reported "colossal" damage, threatening to leave many people without heating in freezing winter temperatures.
The governor of the central region of Dnipropetrovsk reported "serious damage".
Air defences took out 60 out of 76 incoming missiles fired at critical infrastructure, Ukraine's top general said.
Moscow says the attacks are aimed at disabling Ukraine's military, while Kyiv calls them a war crime.
Moscow deliberately tried to distract the air defences by flying warplanes near Ukraine, Air Force spokesperson Yuriy Ihnat said.
"They want to destroy us, and make us slaves. But we will not surrender. We will endure," said Lidiya Vasilieva, 53, as she headed for shelter at a Kyiv railway station.
"I want the war over and soon. But I am ready to wait as long as needed."
Attack on Zelenskyy's hometown
Three people were killed in the central city of Kryvyi Rih, authorities said, and a fourth died in a fire in the southern Kherson region after an apartment block was hit by shelling before the missile strike.
The attack in Kryvyi Rih, President Volodymyr Zelenskyy's hometown, also wounded at least 13 people, including four small children, a senior official said.
Grid operator Ukrenergo warned that repair times would be longer compared with previous ones and that it would take longer to restore power.
"What we already see is damage to about nine [power] generating facilities. Now we are still verifying the damage," Energy Minister German Galushchenko told national television.
The central city of Poltava and parts of Kyiv were among areas where power was knocked out.
Critical infrastructure was hit in the north-eastern region of Kharkiv, the Black Sea region of Odesa and in Vinnytsia in west central Ukraine.
"There is colossal damage to infrastructure, primarily the energy system," Kharkiv Mayor Ihor Terekhov said.
"I ask you to be patient with what is happening now. I know that in your houses there is no light, no heating, no water supply."
Kyrylo Tymoshenko, deputy head of Mr Zelenskyy's office, said emergency power shutdowns had been introduced nationwide to enable repairs.
Subway services in the capital were suspended, he said, as city residents flocked inside its tunnels deep underground to seek shelter.
Ukrzaliznytsia, the national railway operator, said power was out in a number of stations in the eastern and central Kharkiv, Kirovohrad, Donetsk and Dnipropetrovsk regions, due to damage to the energy infrastructure.
Such strikes targeting energy infrastructure have been part of a new Russian strategy to try to freeze Ukrainians into submission after key battlefield losses by Russian forces in recent months.
But some analysts and Ukrainian leaders say such an onslaught has only strengthened the resolve of Ukrainians to face up to Russia's invasion.
Russia calls Ukrainian shelling 'barbaric'
Russian troops occupy around a fifth of Ukraine in its south and east and are trying to extend that amid brutal fighting with many reported killed and wounded on both sides, although neither issues detailed reports of their own military casualties.
Russian-installed officials said the latest Ukrainian shelling had killed civilians in two places.
Eight people were killed and 23 wounded in the village of Lantrativka, close to the border with Russia in the Russian-controlled Luhansk region of Ukraine, the Russian-installed administrator of the region said on Friday.
Leonid Pasechnik called the attack "barbaric".
He said Ukraine was targeting residential neighbourhoods, schools and shopping districts in an attempt to "kill as many people as possible".
He did not provide evidence and there was no immediate comment from Kyiv.
The head of a Russian proxy "people's militia" in Luhansk said a civilian had been killed by Ukrainian shelling in the town of Svatove, some 70 kilometres further south.
Reuters was unable to immediately verify the latest battlefield accounts but recorded three explosions in the snow-covered capital Kyiv and smoke rising over the city.
Wires/ABC