Large areas of Ukraine are suffering blackouts after Russian missiles targeted energy infrastructure.
Fifteen blasts were reported in the second-largest city, Kharkiv, said the mayor, while more than 53,000 households in Odesa were without power.
Ukraine's energy minister, German Galushchenko, accused Russia of trying to provoke "a large-scale failure of the country's energy system".
A power line feeding the Zaporizhzhia nuclear plant had been cut, he added.
Regional governor Ivan Fedorov said the power station was "on the verge of a blackout", adding that seven buildings in the region had been destroyed and 35 others damaged.
President Volodymyr Zelensky said Russia had launched more than 90 missiles and sent 60 explosive drones into Ukraine during the wave of overnight attacks.
At least two people have been reported killed and 14 wounded.
The fresh onslaught comes a day after Russian forces launched one of their biggest air strikes in weeks on the Ukrainian capital, Kyiv. At least 17 people, including a child, were injured by falling debris.
The latest attack prompted President Zelensky to renew his call for more military aid and additional air defence systems from Western allies.
He said that the shortfall in ammunition facing his troops was "humiliating" for Europe, adding: "Europe can provide more, and it is crucial to prove it now."
Ukraine's state hydropower company said a Russian strike had also hit its largest dam, the DniproHES in Zaporizhzhia.
Video footage appeared to show the dam on fire, but there seems to be no threat of imminent breach.
Social media videos showed a trolleybus which was reportedly passing near the dam and caught fire after a missile strike.
Blasts were also reported from Kryvyi Rih, which is President Zelensky's hometown, and Vinnytsia, both in central Ukraine. They damaged a "critical infrastructure object", said Ukrainian officials.
Kharkiv in north-eastern Ukraine also came under attack overnight.
Governor Oleg Synehubov posted on his Telegram channel that there was no electricity in the city after the missile attack.