Russian forces struck gas facilities in eastern Ukraine early Thursday, sparking major disruption to the network in another large-scale bombardment piling pressure on the energy infrastructure.
Moscow has attacked Ukrainian power infrastructure each winter since invading in 2022, forcing Kyiv to impose emergency blackouts and import energy from abroad.
"There are hits and destruction in several regions at once. The operation of a number of critically important facilities has been halted," the CEO of gas company Naftogaz, Sergii Koretskyi, said in a statement.
The Ukrainian energy grid operator announced emergency power cuts in eight regions, and restrictions for all industrial customers.
Ukraine's air force said Russia launched 320 drones and 37 missiles, adding that 283 drones and five missiles were downed.
"This autumn, the Russians use every single day to strike at our energy infrastructure," Ukrainian President Volodymyr Zelensky said.
Media reports earlier suggested around 60 percent of Ukrainian gas production had been halted in recent Russian strikes, and attacks on power stations had cut electricity for hundreds of thousands of people.
Naftogaz board member Natalia Boyko seemed to confirm the reports.
"I won't name the numbers, but they have already circulated in the media. Unfortunately, I won't refute them," she told an economic forum.
Boyko said gas consumption had risen by more than 20 percent in recent days as temperatures drop across Ukraine.
The Kremlin claims its forces only target military facilities.
Kyiv has increasingly responded to Moscow's aerial attacks by carrying strikes on Russian logistics and refineries.
Ukrainian strikes on the Russian-occupied part of the Kherson region left almost 100,000 people without power, Moscow-backed authorities said.
The International Criminal Court last year issued arrest warrants for two top Russian army officials over the attacks on Ukraine's energy facilities, saying they constituted a "war crime" and had inflicted "excessive" harm to civilians.
Kyiv has been appealing to its allies for more air defence systems to protect critical infrastructure and has also launched retaliatory strikes on Russia's oil refineries.
