Russian shelling continued to displace civilians in the east of the country, where three-quarters of the population has fled the frontline region of Donetsk, according to the regional governor, and Ukraine continued to damage Russia's supply routes to the southern front near Kherson.
Ukraine's state nuclear company Energoatom said on Friday evening that both of the plant's two functioning reactors had been reconnected to the grid and were again supplying electricity after they were fully disconnected on Thursday.
"Let me stress that the situation remains very risky and dangerous," President Volodymyr Zelenskiy said in his regular evening address on Friday, praising Ukrainian experts working to "avert the worst-case scenario".
"Any repeat of yesterday's events, meaning any disconnection of the station from the grid, any action by Russia that could provoke the disconnection of reactors, would once again place the station one step away from a catastrophe."
Russia, which invaded Ukraine in February, took control of the nuclear plant in March, though it is still operated by Ukrainian technicians working for Energoatom.
The two sides have traded the blame for shelling near the plant, which on Thursday sparked fires in the ash pits of a nearby coal power station that disconnected the plant from the power grid.
Satellite images showed a fire near the plant but Reuters could not verify its cause.
Zelenskiy also reiterated Ukraine's demand that the UN's nuclear watchdog, the International Atomic Energy Agency (IAEA), be urgently allowed to visit the Zaporizhzhia plant.
Moscow, which has forces based in the plant's complex, said it was doing everything to ensure that an IAEA visit, expected in the coming days, could take place safely. Foreign ministry spokeswoman Maria Zakharova said Ukraine was trying to disrupt such a visit by attacking the plant.
The Kremlin says its aim is to "denazify" and demilitarise Ukraine and remove perceived security threats to Russia. Ukraine and the West say this is a baseless pretext for a war of conquest.
Former Russian President Dmitry Medvedev, an ally of President Vladimir Putin, said in a French television interview on Friday that Russia was prepared to hold talks with Zelenskiy subject to certain conditions, but warned Moscow would not stop its assault until its goals had been achieved.
"Renouncing (Ukraine's) participation in the North Atlantic alliance is now vital, but it is already insufficient in order to establish peace," Medvedev told LCI television.
Ukrainian rocket fire put an important bridge in Kherson region out of action on Friday, Ukraine's southern military command said.
Knocking out the Darivsky bridge, used by Russian forces to cross the Inhulets River just east of the city of Kherson, would complicate Moscow's efforts to supply its troops in the Russian-occupied city that Ukraine wants to take back, it said.
There was no immediate comment from Moscow.
The Ukrainian military general staff said Russian aircraft attacked several sites, focusing on more than a dozen towns in the south including the city of Mykolaiv, a river port lying just off the Black Sea.
There were also air strikes against towns in the Sumy region near the Russian border, the general staff said, and Russian forces had shelled and carried out air attacks against the Kharkiv region in the northeast.
Pavlo Kyrylenko, governor of the eastern Donetsk region, said three-quarters of its population had been fled.
"There is practically not a single major town or city that is not subject to (Russian) shelling," he told Ukrainian TV.
Russian state news agency TASS said the deputy traffic police chief in the occupied Ukrainian city of Berdiansk was killed on Friday in a bombing, which the Russian-installed administration blamed on "Ukrainian saboteurs".
Ukraine's defence ministry did not respond to a request for comment.
