Kyiv authorities said missiles caused fires in a supermarket building, houses and a market. (File)
Russia on Tuesday rained missiles on Ukraine's two main cities, killing four people and injuring dozens while 250,000 consumers in the capital region were left without power in near-freezing temperatures.
The attacks on the capital Kyiv and the northeastern city of Kharkiv came less than 24 hours after Russian President Vladimir Putin said Moscow would intensify strikes.
"One wounded elderly woman from a building in the Solomyansky district... died in an ambulance. Twenty-seven wounded people were hospitalised," Kyiv mayor Vitaly Klitschko said.
Ukraine's interior minister Igor Klymenko said two people were killed in the Kyiv region.
National energy company Ukrenergo said 250,000 consumers were without electricity in Kyiv and surrounding areas after the strikes. Temperatures in the region were hovering around three degrees Celsius (37.4 degrees Fahrenheit).
The head of Kharkiv Oleg Sinegubov said one woman was killed in the northeastern city in attacks denounced Tuesday by Ukrainian President Volodymyr Zelensky as "Russian terror".
Kyiv authorities said missiles caused fires in a supermarket building, houses and a market.
Strikes in Kharkiv wounded over 40 people and damaged multi-storey buildings, said the head of the city's military administration, Oleg Sinegubov.
The Ukrainian air force said Russia was launching Kinzhal missiles.
In a sign of growing concern, Poland on Tuesday scrambled four F-16 fighter jets to its border with Ukraine to protect its airspace.
Poland -- a NATO and EU member -- is a staunch ally of Ukraine as the Russian invasion nears its second anniversary.
During the last wave of deadly attacks on Ukraine on Friday, Poland said a Russian missile had passed through its airspace.
Tuesday's attacks came after an escalation in the war in recent days.
Putin on Monday called an unprecedented Ukrainian attack on the Russian city of Belgorod a "terrorist act" and vowed retaliation.
Moscow also attacked Ukraine with a barrage of drones on New Year's Eve.
Ukraine is seeking assurances from its backers that military aid will continue as any new budget for support is stalled in Washington.
'Critical we support Ukraine'
"Putin is ringing in 2024 by launching missiles at Kyiv and around the country as millions of Ukrainians take shelter in freezing temps. Loud explosions in Kyiv this morning," US Ambassador to Ukraine Bridget Brink wrote on X.
"It's urgent and critical that we support Ukraine now -- to stop Putin here."
Kyiv mayor Klitschko reported multiple explosions and debris from downed missiles hitting the capital as residents were advised to stay in underground shelters.
In the Pechersk district, debris hit the roof of a nine-storey building and another building, the military administration said.
Fires also broke out in a supermarket and a warehouse measuring 2,000 square metres, the mayor said.
"As soon as the security situation allows it, we will definitely restore electricity to everyone," the city's military administration said.
In the city's Podil district, main water pipes have been damaged, it added.
The attacks came after Russia on December 29 launched a wave of strikes across Ukrainian cities, including Kyiv, which killed 39 people.
Moscow also hit Ukrainian cities on New Year's Eve, with Kyiv saying it had foiled a "record" number of drones launched by Russia.
(Except for the headline, this story has not been edited by NDTV staff and is published from a syndicated feed.)