Ukrainian President Volodymyr Zelensky on Wednesday denounced an “inhumane” attack from Russia, which launched over 170 missiles and drones on his war-torn country’s power grid on Christmas Day, killing an energy worker.

The country woke up at 5:30 am (0330 GMT) to an air raid alarm, shortly followed by air force reports that Russia had launched Kalibr cruise missiles from the Black Sea.

“Putin deliberately chose Christmas to attack. What could be more inhumane? More than 70 missiles, including ballistic missiles, and more than a hundred attack drones. The target is our energy system,” Zelensky said.

This was the 13th large-scale strike on Ukraine’s energy system this year, the latest in Russia’s campaign targeting the power grid during winter.

Russia meanwhile said five people had died in Ukrainian strikes and a falling drone in the border region of Kursk and in North Ossetia in the Caucasus.

Ukraine said its air force downed 58 out of 79 Russian-launched missiles. It did not, however, down the two Korean KN-23 ballistic missiles launched by Russia.

British Prime Minister Keir Starmer condemned the strikes.

“I pay tribute to the resilience of the Ukrainian people, and the leadership of President Zelensky, in the face of further drone and missile attacks from Putin’s bloody and brutal war machine with no respite even at Christmas,” Starmer said.

Kyiv also said a Russian missile went through Moldovan and Romanian airspace, but Romania said it detected no such violation while Moldova said it launched investigations.

“Unfortunately, there are some hits. As of now, there are blackouts in several regions,” Zelensky said.

Ukraine’s DTEK energy company said the attack severely damaged equipment of thermal power plants.

“Denying light and warmth to millions of peace-loving people as they celebrate Christmas is a depraved and evil act that must be answered,” DTEK CEO Maxim Timchenko said, urging allies to send more air defence.

The employee of a Ukrainian thermal power plant was killed in the central Dnipropetrovsk region, over which 42 missiles were shot down, governor Sergiy Lysak said.

Lysak also said rescue operations had been completed on the site of a strike on Kryvyi Rig, which killed one person and wounded 17 others the day before.

Engineers have restored power to consumers in the Ivano-Frankisvk region.

“Christmas morning has once again shown that nothing is sacred for the aggressor country,” Svitlana Onyshchuk, the head of the Ivano-Frankivsk region, said earlier.

Ukraine is officially celebrating Christmas on December 25 for the second time.

The government last year changed the date from January 7, when most Orthodox believers celebrate, as a snub to Russia.

The Christmas day attack also targeted Kharkiv, Ukraine’s second largest city, located near the Russian border.

The missiles had targeted the city’s boiler houses, thermal power plants and electricity facilities, mayor Igor Terekhov said, temporarily cutting power to 500,000 people.

One unexploded missile was found in a private yard in Kharkiv, Synegubov said.

Kharkiv’s governor Oleg Synegubov also said authorities had evacuated 46 people from the area of Borivske and Kupiansk.

Moscow’s forces are aiming to recapture the town of Kupiansk, which was occupied in the first year of the war.

Ukraine recaptured it in September 2022 as part of a lightning offensive that saw its forces regain large swathes of the Kharkiv region.

Outnumbered Ukrainian troops are on the back foot across the front line in the Kharkiv and Donetsk region further south, ceding ground to better-equipped Russian troops.

Russia said it seized the small village of Vidrodzhennia, a few kilometres south of the vital rail and mining hub of Pokrovsk.

Both sides are scrambling to gain an upper hand ahead of the inauguration of US president-elect Donald Trump, who boasted he would quickly end the war, raising fears that Washington may force Kyiv into a deal on Moscow’s terms.

Ukraine has been urging allies to send more aid to fend off aerial strikes and push back troops on the ground.

“I am grateful to everyone who is working for the country, who is on combat duty, who is protecting our sky,” Zelensky said.

“Russian evil will not break Ukraine and will not ruin Christmas,” Zelensky said.