People take shelter inside a metro station in Kyiv during Russia's overnight attack.
Kyiv, Ukraine CNN  — 

More than a million households were left without power in Ukraine after a widespread Russian aerial attack targeted critical energy infrastructure facilities, authorities in the country said Thursday.

This is Russia’s 11th large-scale assault on Ukraine’s energy supplies this year alone, according to the energy ministry in Kyiv, a strategy which has caused nationwide rolling blackouts. Bombardments have intensified in recent months, leaving Ukraine in a precarious position as the war grinds into its third winter.

Ukraine’s energy system came “under massive enemy attack,” overnight, Energy Minister German Halushchenko said Thursday, adding the attacks took place “all over Ukraine.”

Ukraine’s energy operator introduced emergency power cuts in many regions, with large outages in the western regions of Lviv, Volyn and Rivne.

At least five people were injured, including one person in the central Vinnytsia region, two in the southern Odesa region, and two in the capital Kyiv, officials said. In the city of Kharkiv, a missile struck a civilian business, according to local military authorities.

Air defenses were activated across the country, including in Kyiv, the capital’s mayor Vitaliy Klitschko said. The city’s residents took shelter in metro stations as the air raid alert lasted for more than nine hours, due to the combined missile and drone attack. There were no immediate reports of casualties there, authorities said.

“This morning I heard about three explosions,” Valeriy Dorotiy, a resident of Lutsk, in western Ukraine’s Volyn region, told CNN. He said he couldn’t tell if the blasts were from missiles or Ukrainian air defense interceptions. “After that, the power went out.”

About 215,000 households in the Volyn region were temporarily without power, authorities said earlier.

“I have a power bank for charging my phone, but I did not buy a more powerful station because I did not take it seriously that there would be such attacks and that missiles would reach us,” Dorotiy said, adding that it seemed Russia was concentrating on attacking eastern Ukraine instead. “But it did reach us.”

Kyiv resident Olha Vaynrikh, 32, told Reuters, “Our mornings begin with checking the phone to see if there is an air alert… We are indeed fed up with all of it.”

The attack marks Russia’s 11th large-scale assault on Ukraine’s energy infrastructure this year alone.

The onslaught involved about 100 drones and more than 90 missiles, according to Ukrainian President Volodymyr Zelensky.

“Every attack like this proves that air defense systems are needed in Ukraine now, where they save lives, not at storage bases,” Zelensky added, urging allies to help his country increase its air defense capabilities.

This comes after Russia launched a record 188 drones at Ukraine on Tuesday in a mass attack that damaged critical infrastructure in the west of the country, according to the Ukrainian Air Force.

This is a developing story and will be updated.