Russia launched a barrage of missiles and drones on Saturday, damaging energy facilities in five regions across Ukraine, officials said.

Ukraine’s national grid operator Ukrenergo said the attack damaged energy facilities in the eastern Donetsk, southeastern Zaporizhzhia, and Dnipropetrovsk regions, central Kyrovohrad region, and Ivano-Frankivsk region in the west.

“Today morning the Russians launched another strike on Ukrainian energy facilities. Since March it is already the sixth massive, complex, missile and drone attack against the civilian energy infrastructure,” Ukrenergo said.

Ukrainian air defence shot down 35 of 53 Russian missiles and 46 of 47 Russian drones, the air force commander said.

Since March, Russia has stepped up its bombardments of the Ukrainian power infrastructure, knocking out the bulk of the thermal and hydropower generation, causing blackouts, and pushing electricity imports to record highs.

DTEK, Ukraine’s largest private energy-generating company, said that during the attack its two thermal power plants had been hit and equipment “seriously damaged.”

Regional officials reported that firefighters were extinguishing fires on several sites following the strikes. There were no immediate reports of casualties.