A Russian missile and drone barrage damaged a Ukrainian power plant and other energy facilities overnight, officials said on Thursday, the latest in a series of strikes that have pushed its grid to the brink.
The targeted aerial barrages over recent months have crippled Ukrainian electricity generation capacity and forced officials to impose rolling blackouts and import supplies from neighboring EU states.
"The enemy attacked a number of energy infrastructure facilities," the energy ministry said, adding that the barrage of Russian projectiles targeted energy-linked sites in four regions, including the capital, without elaborating.
AFP journalists in the capital heard air raid sirens ringing out over the capital in the early hours of Thursday.
DTEK, Ukraine's largest private energy company, said the aerial attacks had caused "serious damage" at one of its thermal power plants, and that three of its employees had been wounded in the attack.
"This is already the seventh mass attack on the company's thermal power plant in the last three months," the company said.
President Volodymyr Zelensky has said that those attacks have halved generator capacity in the war-battered country compared to one year ago and urged allies to send more air defence systems to protect vital infrastructure.
DTEK's CEO Maxim Timchenko said that the power plant struck early on Thursday had already been damaged in previous attacks.
"We urgently need to close our skies or Ukraine faces a serious crisis this winter. My plea to allies is to help us defend our energy system and rebuild in time," he said.
There was no immediate comment from the Kremlin on the latest barrage but Moscow insists that its forces do not target civilian infrastructures.
The Russian defence ministry has, however, acknowledged retaliatory attacks on energy sites in response to a wave of Ukrainian cross-border attacks on Russian oil facilities, mainly storage sites.
In the latest Ukrainian attack on Russian territory, the governor of Russia's Krasnodar region, which borders the annexed Crimean peninsula, announced one woman had been killed in a drone attack targeting oil facilities.
Among the areas struck was the city of Slavyansk-on-Kuban in Krasnodar region, where the woman was killed, governor Venyamin Kondratyev said.
The Russian defence ministry said it had downed 15 Ukrainian drones that also targeted oil storage depots in the southern Adygea republic and in the Tambov region.
There was no immediate claim from Ukraine but sources in its security services have claimed responsibility for previous similar attacks, with the aim of hurting Russian oil revenues.
Ukraine's air force said that Russia had launched nine missiles and 27 Iranian-designed attack drones, and that air defence systems had downed all the projectiles except four missiles.
It also confirmed that "critical infrastructure" facilities were targeted, including in the Dnipropetrovsk region, one of the regions in which DTEK operates.
It said air defence systems were also activated in the regions of Zaporizhzhia, Donetsk, Kherson, Kharkiv and Kyiv, among others.
Russia has meanwhile stepped up fatal artillery attacks on embattled frontline regions of Ukraine, in the south and the east of the country.
The governor of the southern Kherson region announced on Thursday morning that one person had been killed and three wounded over the last 24 hours.
In Kharkiv, a northeastern region where Russia recently launched a surprise ground offensive, the governor said one woman had been killed by Russian fire.
And in the eastern Donetsk region, the governor said two people had been killed, one in the frontline town of Toretsk where Russian forces have gained ground after attacking following a long lull in fighting there.