KYIV — The Russian army attacked Ukraine with more than 90 killer drones in the early hours of Thursday morning, causing complete blackouts in the key industrial regions of Dnipro and Zaporizhzhia, Kyiv’s energy ministry reported.

“While energy workers managed to restore power in the Zaporizhzhia region in the morning, some 800,000 households in the nearby Dnipro region were still without electricity and heating on Thursday morning,” Artem Nekrasov, acting energy minister of Ukraine, said during a morning briefing.

In Dnipro, eight coal mines stopped working because of a power outage. All the miners were safely evacuated to the surface, Nekrasov added. Power outages were also reported in Chernihiv, Kyiv, Ivano-Frankivsk, Poltava and other regions.

Freezing weather is coming to Ukraine over the next three days, with temperatures forecast to drop to minus 20° C during the night, when Russia often launches massive missile and drone attacks.

Precipitation and cold could cause additional electricity supply disruptions due to snow accumulating on power lines, Ukrainian Prime Minister Yulia Svyrydenko said Wednesday evening.

“Ukraine’s energy system is under enemy attack every day, and energy workers work in extremely difficult conditions to provide people with light and heat. Deteriorating weather conditions create additional stress on critical infrastructure. We are working to minimize the consequences of bad weather,” Svyrydenko added.

Local governors in the eastern regions of Zaporizhzhia and Dnipro reported that hospitals and other critical infrastructure had to turn to emergency power supplies because of the latest Russian attack.

President Volodymyr Zelenskyy thanked Ukrainian energy workers for the speedy power restoration in Zaporizhzhia, and used the opportunity to remind Kyiv’s partners around the world they need to respond “to this deliberate torment of the Ukrainian people by Russia.”

“There is absolutely no military rationale in such strikes on the energy sector and infrastructure that leave people without electricity and heating in wintertime. This is Russia’s war specifically against our people, against life in Ukraine — an attempt to break Ukraine,” Zelenskyy added.