Wednesday's strikes, in which Ukrainian officials said seven people were killed, followed days of intensifying drone barrages primarily on the capital, a prelude to what many Ukrainians expect to be a winter of attacks intended to plunge cities into cold and darkness when Ukraine is short of air defences.
Ukraine's state power grid operator Ukrenergo said it had imposed emergency power cuts as a result of the attack in Kyiv and three surrounding regions — the first time such a measure had been imposed in the capital since the spring.
Russian attacks last winter, which brought record-low temperatures, ravaged power and heating systems, forcing Ukrainians to adapt to dire circumstances.
"Russia has escalated to massive strikes on energy infrastructure," Prime Minister Sergii Koretskyi said on X after the attacks overnight.
"Since summer, there's barely been a day without an attack on our energy infrastructure. But a combined strike of this scale hasn't happened since the end of last heating season."
Kyiv residents awoke on Wednesday to a city shrouded in fog from the smoke of attacks, which authorities said damaged a key power plant and other energy facilities around the capital.
Ukraine's air force said its air defences had intercepted 254 of 285 Russian drones deployed until early evening.
It said 174 drones were high-flying and faster jet-propelled models, which are harder to intercept. Russian forces had also launched a ballistic missile attack.
A child was among the seven dead across Ukraine, President Volodymyr Zelenskiy said, with critical infrastructure coming under attack in five regions. Further damage was reported in another five regions, he added.
Zelenskiy visited a military command post near the town of Lyman near the eastern frontline and praised what he said were gains against Russian forces during a counteroffensive.
He said Ukrainian forces had recaptured 176sq km of territory since the start of the operation.
Russia said its forces had struck power plants in the Kyiv region, an industrial complex in Odesa region, and port infrastructure in Ismail in the southwest.
Drone strikes continued in Kyiv into the early evening.
Near-constant daytime sirens and explosions have become a fixture of daily life in Kyiv, where drone attacks have killed around a dozen people over the past week alone.
Ukrainian Foreign Minister Andrii Sybiha described Wednesday's attack by Russia as a "deliberate" distraction from its grinding battlefield offensive in eastern Ukraine, which has slowed since 2025.
Forecasters say they expect freezing temperatures at night in Kyiv in the coming days.
Russia, which began its full-scale invasion in February 2022, denies targeting civilians although it has pounded cities and towns across Ukraine.
Authorities in recent weeks and months have been building protective facilities and aiming to diversify energy generation before Russia's expected winter campaign.
However, Ukrainian human rights ombudsman Dmytro Lubinets said there was a critical shortage of urban shelters, describing the civil-defence system as having "completely failed".
In Moldova, on Ukraine's western border, the defence ministry said three drones had crossed into its airspace over the course of the day.
NATO members Romania and Poland both scrambled military jets, the countries said, and flights at the Polish airports of Lublin and Rzeszow were suspended for a time.
Ukraine has also stepped up attacks on Russia, striking oil refineries and online retailers to undermine its war effort.
