KYIV, Ukraine (AP) — Russia on Wednesday launched a major ballistic and cruise missile attack on regions across Ukraine, targeting energy production and compelling authorities to shut down the power grid in some areas despite freezing winter weather, officials said.

The Russian Defense Ministry said that it launched a strike on “critically important facilities of gas and energy infrastructure that ensure the functioning of Ukraine’s military industrial complex.” It didn't give the target locations or other details.

The barrage came a day after the Russian Defense Ministry vowed a response to what it said was an attack on Russian soil using multiple Western-supplied missiles.

Kyiv hasn't confirmed that attack, though it said Tuesday that it hit an oil refinery and a fuel storage depot, a chemical plant producing ammunition and two anti-aircraft missile systems, in a missile and drone attack that reached around 1,100 kilometers (almost 700 miles) into Russia.

Long-range attacks have been a feature of the nearly three-year war, where on the front line snaking about 1,000 kilometers (600 miles) from northeast to southern Ukraine, the armies have been engaged in a war of attrition. Russia has been advancing on the battlefield over the past year, though its progress has been slow and costly.

Ukraine's defenses have been under severe pressure for months in the eastern Donetsk region, where Russian forces are bent on capturing the key stronghold of Pokrovsk.

The situation there is “critically bad” as Russian forces are intent on cutting off the Dnipro highway, which is a vital supply route for Pokrovsk, Serhii Filimonov, commander of the 108th Separate Mechanized Battalion, told The Associated Press on Wednesday.

Russia attacked Ukraine with 43 missiles and 74 drones before dawn Wednesday, the Ukrainian Air Force said. A total of 30 missiles and 47 drones were shot down, and 27 drones failed to reach their target, it said.

The Russian missiles sought out targets from the Lviv region in western Ukraine near Poland to Kharkiv in northeast Ukraine bordering Russia. The state energy company Ukrenergo reported emergency power outages in six regions. It often shuts down production during attacks as a precaution.

“The enemy continues to terrorize Ukrainians,” Energy Minister Herman Halushchenko wrote on Facebook.

Electricity supplies resumed to households in some areas by the middle of the day, but Ukrenergo urged customers to avoid using power-hungry electrical appliances.

Russia has repeatedly tried to cripple Ukraine’s power grid, denying the country heat, electricity and running water in an effort to break the Ukrainian spirit. The attacks have also sought to disrupt Ukraine’s defense manufacturing industry.

Last September, the U.N. refugee agency reported that Ukraine had lost more than an estimated 60% of its energy generation capacity.

Ukrainian authorities try to rebuild their power generation after the attack, though the barrages have eroded production. Western partners have been helping Ukraine rebuild.

“It is the middle of the winter, and Russia’s goal remains unchanged: our energy infrastructure,” Zelenskyy said on Telegram.

He urged Western partners to accelerate the delivery to Ukraine of promised air defense weapons, emphasizing that “promises have been made but not yet fully realized.”

Meanwhile, Russia and Ukraine each exchanged 25 prisoners of war under the latest swap brokered by the United Arab Emirates, officials said.