President Volodymyr Zelensky called in an Easter Sunday message for Ukrainians to defend themselves against Russian aggression.
"Now there is no night or day when Russian terror does not try to break our lives," Zelensky said in a post written in English on X, the platform formerly known as Twitter.
Ukraine came under Russian attack in the early hours of Sunday, with energy infrastructure a particular target. The Ukrainian air force reported intercepting 18 of 27 attacks from drones, missiles and cruise missiles, but the authorities reported that some had struck their targets.
One person died in Lviv in the west of the country when infrastructure came under attack.
Tens of thousands were without power for a time in the Odessa region on the Black Sea, and power cuts were reported in other parts of the country as well.