Russia launched 400 drones and one ballistic missile, primarily targeting Kharkiv, Kryvyi Rih and Vinnytsia - three cities in different parts of Ukraine, Ukraine's air force said early on Wednesday.
It said it had shot down most of the drones, but 12 unspecified targets were hit by the missile and in attacks by 57 drones.
National emergency services reported two deaths in drone strikes east of the northeastern city of Kharkiv near the town of Kupiansk, an area which has been under Russian attack for several months.
The head of the military administration in the southeastern city of Kryvyi Rih, Oleksandr Vilkul, said Russian forces carried out an extended attack with a missile and 28 drones.
Power and water supplies had been disrupted in some areas, he said.
Vilkul said a 17-year-old boy was severely injured in the attack.
In Vinnytsia and the surrounding region, eight people were wounded, according to Ukraine's interior ministry.
In Kharkiv, a frequent target of Russian attacks, regional Governor Oleh Syniehubov said at least 17 explosions were recorded in a 20-minute drone attack in which three people were injured.
Kyiv Mayor Vitali Klitschko said air defence units had gone into action for a time in the capital, but there were no reports of casualties or damage.
Russian forces have stepped up air attacks on Ukrainian cities, with record numbers of drones being fired last week.
"Russia is not changing its strategy - and to counter this terror effectively, we need to systematically strengthen our defences: more air defence systems, more interceptors, and more determination - so that Russia feels our response," Zelenskiy posted on X.
Ukraine's military has also attacked Russian targets, often linked to the energy system.
Both sides deny targeting civilians in their strikes during the war that Russia launched against Ukraine more than three years ago.
But thousands of civilians have died in the conflict, the vast majority of them Ukrainian.
