The Ukrainian capital and other cities came under fire from missiles and Iranian-made drones on Saturday, killing three people. A new attack Sunday killed one in the southern region of Zaporizhzhia.
Kyiv was again rocked by an air raid on Monday morning, with the city´s military administration ordering residents just after 1:00 am to retreat to "stay in shelters."
"The air defense (system) is working... Fragments of balconies and windows in a high-rise building were damaged in Desnyanskyi district," Serhiy Popko, head of the city´s administration, said on the Telegram messaging app.
Oleksii Kuleba, head of the Kyiv region military administration, said there were "waves" of attacks by Iranian-made Shahed drones.
"They are targeting critical infrastructure facilities," he said.
Nearly three hours later, the capital and its surrounding region lifted the air alert. The city´s military administration said 20 air targets had been shot down.
Mayor Vitali Klitschko reported an explosion in Kyiv´s northeastern Desnyanskyi district and said emergency services were dispatched.
"An injured 19-year-old man was hospitalized in the Desnyanskyi district of the capital," he said. Authorities later said the falling debris cut him.
Russia´s New Year assaults- targeted downtown areas of large cities- show a change in tactics, said an adviser to Ukrainian President Volodymyr Zelensky.
"Russia no longer has any military goals and is trying to kill as many civilians as possible and destroy more civilian facilities," Mykhailo Podolyak tweeted.
"A war to kill."
The attacks came as President Vladimir Putin´s invasion of Ukraine enters its 11th month.
On Saturday, Russian artillery hit the village of Naddniprianske outside the city of Kherson, severely wounding a 13-year-old boy.
Then the Russian army struck the hospital where the boy was lying in intensive care, smashing the windows.
"What did the 13-year-old boy do to these Inhumans that they tried to kill him twice?" governor Yaroslav Yanushevych said on messaging app Telegram.
The Russian onslaught damaged the Kherson hospital and left the city and the surrounding settlements without electricity.
Russian forces in November withdrew from Kherson, the only regional capital held by Moscow, but have continued to batter the city.
Ukrainian governors and officials also reported one death each in Orikhiv in the Zaporizhzhia region, in the capital Kyiv, in the southern region of Kherson, and in the western city of Khmelnytskyi.
Dozens of people were also wounded, they said.
Kyiv Police Chief Andriy Nebitov released a picture of the wreckage of a downed drone that featured the words "Happy New Year" in Russian.
"That is everything you need to know about the terror state and its army," he wrote.
The Ukrainian air force said 45 Iranian-made drones had been destroyed overnight from Saturday to Sunday.
"Thanks to our air force, pilots, anti-aircraft gunners... Well done, guys!" Zelensky said in his nightly address on Sunday.
In the eastern region of Donetsk, pro-Russian officials said Ukrainian shelling had killed a civilian in the town of Yasynuvata.
After several humiliating battlefield defeats, Moscow started targeting electrical and other critical infrastructure in October.
The strikes have caused sweeping blackouts and cut off water supplies, and heating to civilians as the temperature in some regions dropped below freezing.
The UN´s human rights chief has warned that the campaign has inflicted "extreme hardship" on Ukrainians and decried probable war crimes by Russian forces.
But Putin declared during his midnight New Year´s Eve address that "moral, historical rightness is on our side."
Moscow said it's New Year´s attacks had targeted the pro-Western country´s drone production.
"The plans of the Kyiv regime to carry out terror attacks against Russia shortly have been thwarted," Russia´s defense ministry said.
Russia has accused Ukraine of targeting its domestic military sites and infrastructure.
In December, Moscow said it had shot down drones three times over Engels airfield, an airbase in southern Russia more than 600 kilometers (370 miles) from Ukraine.
Another base in Russia´s Ryazan region also saw attacks from Ukraine´s drones in early December, according to Moscow, killing three people.
Kyiv has a policy of not claiming responsibility for such raids.