KYIV  -   Russia launched a “massive” missile strike at Ukraine overnight, damaging four power plants in the latest barrage targeting the country’s energy supply, officials in Kyiv said on Saturday.

Ukrainian President Volodymyr Zelensky called on Kyiv’s Western partners to supply more air defence systems to protect his country’s skies, as the air force said it shot down 21 of 34 incoming missiles. Moscow has launched some of its biggest ever strikes on Ukraine’s energy facilities in recent months, knocking out a significant chunk of production, and triggering blackouts and energy rationing across the country.

Ukraine also said it hit two oil refineries and a military air base in southern Russia its own wave of overnight drone attacks. “Thirty-four Russian missiles overnight. We managed to shoot down some of them. But the world has every opportunity to help (us) shoot down every missile and every drone,” Zelensky said in a post on Telegram.

Energy facilities were hit in at least three regions -- including Lviv and Ivano-Frankivsk in the west, hundreds of kilometres from the front line -- Energy Minister German Galushchenko said in a Facebook post.

One of the missiles landed 15 kilometres (nine miles) from the Polish-Ukrainian border, Poland’s Prime Minister Donald Tusk said. Kyiv says Moscow is escalating attacks from the air and on land ahead of nationwide celebrations on May 9, when Russia marks victory in World War II, and while Ukraine awaits the arrival of crucial US weapons. The DTEK power operator said equipment at four of its thermal power plants was “severely damaged” in the overnight strikes. 

State electricity operator Ukrenergo said it had disconnected its main overhead power line in the west of the country as a preventative measure. Officials urged people and businesses to limit their power usage.