Ukrainian President Volodymyr Zelensky called for a stronger international response to what he described as Russian "nuclear terror" after shelling at the Zaporizhzhia nuclear power plant, the biggest in Europe.
During a phone call with European Council President Charles Michel, he called for sanctions to be imposed on the Russian nuclear industry and nuclear fuel, the Ukrainian leader wrote on Twitter.
Ukraine's state nuclear power company said earlier that a worker had been wounded when Russian forces shelled the Zaporizhzhia nuclear power plant yesterday evening.
Energoatom, operator of the Zaporizhzhia nuclear power plant in the south of the country, said parts of the facility had been "seriously damaged" by military strikes and one of its reactors was forced to shut down.
Friday's strikes had damaged a station containing nitrogen and oxygen and an auxiliary building, Energoatom said on the Telegram messaging service.
As hostilities raged on in the east and south of Ukraine, pro-Moscow authorities in the Russian-occupied Kherson region reported the assassination of a senior official.
Meanwhile the head of Amnesty International's Ukraine office announced she had resigned from the organisation over the group's publication of a controversial report that accused the country's military of endangering civilians.
Amnesty secretary general Agnes Callamard expressed regret at her departure and paid tribute to her work. But the organisation stands by its report.
In his address last night, Mr Zelensky also hit out at Amnesty International, comparing the rights group's accusations against Ukraine's military with its silence on Russia's actions.
Referring to the strikes on the Zaporizhzhia plant, he said that although they represented "one of the most dangerous crimes against Ukrainians and all Europeans... for some reason, there's still no report or even just a simple message from Amnesty International about it.
"It's a very eloquent silence, which points out, once more, a manipulative selectivity of this organisation," he added.
Ukraine and Russia have blamed each other for the attacks on the Zaporizhzhia plant, Europe's largest atomic power complex.
President Zelensky, in his nightly address, once again accused Moscow of terrorism, saying, "Russian terrorists became the first in the world to use the power plant... for terror."
The head of the UN's nuclear watchdog expressed alarm over the shelling at the plant.
The strikes underline "the very real risk of a nuclear disaster", said Rafael Grossi, director general of the International Atomic Energy Agency (IAEA).
"Any military firepower directed at or from the facility would amount to playing with fire, with potentially catastrophic consequences," he added.
The European Union's top diplomat Josep Borrell condemned the attack "as a serious and irresponsible breach of nuclear safety rules and another example of Russia's disregard for international norms".
An official with the Russian occupying authorities in Kherson died in hospital after being shot yesterday, Russian state media reported.
Vitalii Hura, "the deputy head of the Novaya Kakhovka administration in charge of the housing and utility sector, died from his wounds", Yekaterina Gubareva, the deputy head of Russia's civil-military administration in Kherson, wrote on Telegram, according to TASS.
The report said Mr Hura had been attacked in his home and shot several times.
Another Russian-appointed official was killed in the same region in June, reportedly by a bomb planted in his car.
There has been a spate of reported assassination attempts and attacks against pro-Kremlin officials in Ukrainian regions controlled by Russia.
Although Russia has seized a large swath of the Kherson region and part of nearby Zaporizhzhia in recent months, Ukraine's forces have reclaimed some territory.
It comes as four ships carrying Ukrainian food stuffs sailed from Black Sea ports today as part of a deal to unblock the country's sea exports, Ukrainian and Turkish officials said.