Ukraine accused the Kremlin of "nuclear terror" and the West expressed fury on Friday after Europe's largest atomic power plant was attacked and seized by invading Russian forces, who continued to shell major cities.
The fighting and a fire at the plant at Zaporizhzhia triggered an emergency meeting of the UN Security Council, and came as President Vladimir Putin intensified a crackdown on opposition in Russia to his nine-day-old war.
The six reactors at Zaporizhzhia, which can power enough energy for four million homes, were apparently undamaged by the fire in a training facility. Monitors reported no spike in radiation.
But the attack killed three Ukrainian soldiers, according to Kyiv's nuclear operator Energoatom, and was slammed by Western capitals, NATO and environmental groups as utterly irresponsible.
"We survived a night that could have stopped the story, the history of Ukraine, the history of Europe," Ukrainian President Volodymr Zelensky said.
An explosion at Zaporizhzhia would have equalled "six Chernobyls", he said, referring to the plant in Ukraine that was the site of the world's worst nuclear disaster in 1986.
"Russian tank commanders knew what they were firing at," Zelensky alleged, adding: "The terrorist state now resorted to nuclear terror."
Russian defence ministry spokesman Igor Konashenkov claimed the attack on Zaporizhzhia was staged by "Ukrainian sabotage groups, with the participation of foreign mercenaries".
"This shows the Kyiv regime's criminal plan," he alleged, adding that the plant had been secured by Russian troops and was functioning normally.
After phoning Zelensky during the night, British Prime Minister Boris Johnson accused Putin of "reckless actions" that could "threaten the safety of all of Europe".
At the urging of Johnson and Western allies, the UN Security Council was convening after the attack, although Russia's veto on the world body would stymie any concerted condemnation.
"We are faced together with what is President Putin's war of choice, unprovoked, unjustified, and a war that is having horrific, horrific consequences," US Secretary of State Antony Blinken said in Brussels.
"We're committed to doing everything we can to make it stop."
But Putin has been unrepentant as Russia has become an economic, sporting and cultural pariah.
The Kremlin said that Putin, in a call Friday with one of his few remaining allies President Alexander Lukashenko of Belarus, restated his view that "the tasks set for the (Ukraine) operations are going according to plan and will be fulfilled in their entirety".
Kremlin spokesman Dmitry Peskov called on Russians "to unite around our president", after thousands braved mass arrests at anti-war demonstrations this week.
Authorities have imposed a news blackout and two liberal media groups have halted operations. On Friday, Facebook and multiple media websites including the BBC were partially inaccessible in Russia.
And Russian lawmakers approved legislation to impose fines and jail terms of up to 15 years for anyone publishing "fake news" about the army.
Western social media companies "carry hatred and lies" against Russia, parliament chairman Vyacheslav Volodin said.
But some Russians appear keen to bypass their state-controlled media.
The BBC says the audience of its Russian-language news website has more than tripled this week, to a record 10.7 million people, and the UK broadcaster vowed to keep the service running.
Russia has intensified strikes across Ukraine with fresh reports of civilian casualties and devastating damage, particularly in southern areas near Kherson, the first city to fall to Moscow's troops.
In a second round of talks held Thursday, Moscow agreed to a Ukrainian request for humanitarian corridors to allow terrified residents to flee.
But there was no clarity on how the corridors would work, and no sign of any move towards a ceasefire.
Ahead of a third round of talks this weekend, Zelensky urged the West to step up military assistance and to "give me planes". He also called for direct talks with Putin.
NATO, fearful of provoking its own war with nuclear-armed Russia, again ruled out enforcing a no-fly zone over Ukraine. And the Kremlin rejected direct talks, insisting any contacts should come via negotiators.
Ukrainian leaders warn that Russia -- given signs that its offensive on the capital Kyiv has stalled -- is bent on reprising the horrific tactics that it used to level the Syrian city of Aleppo in 2016.
The port city of Mariupol, east of Kherson, is cut off without water or electricity in the depths of winter.
Mariupol's deputy mayor Sergei Orlov told BBC radio that its humanitarian situation was "terrible", after 40 hours of continuous shelling including on schools and hospitals.
"Today Putin style of war is like Aleppo. So Mariupol goes to Aleppo," Orlov said in English.
"I believe that he wants to destroy Ukraine as a nation, and Mariupol is on this way."
In the northern city of Chernihiv, 47 people died Thursday when Russian forces bombed residential areas, including schools and a high-rise apartment block, according to a new toll given by local officials.
According to the UN, at least 331 civilians have died since Russia invaded in the night of February 24, purportedly to erase a Western-leaning, "Nazi" threat on its borders.
Ukraine says it has killed thousands of Russian troops. Moscow on Wednesday said it had lost 498 soldiers.
Ukraine authorities say residential parts of the eastern city of Kharkiv have also come under indiscriminate shelling, which UN prosecutors at The Hague are investigating as a possible war crime.
Ukraine's Foreign Minister Dmytro Kuleba demanded a special tribunal, alleging there were "numerous cases of, unfortunately, when Russian soldiers rape women in the Ukrainian cities".
In Geneva, the UN Human Rights Council overwhelmingly voted to create a top-level investigation into violations committed in the invasion.
"The message to Putin has been clear: you're isolated on a global level and the whole world is against you," Ukrainian ambassador Yevheniia Filipenko said after the vote.
The UN says more than 1.2 million refugees have flooded from Ukraine into neighbouring countries.
Both the EU and the United States said they would approve temporary protection for all refugees fleeing the war.
It is also driving some Russians to flee the country, fearful it is their last chance to escape the economic pain from ever-tougher Western sanctions, or the Kremlin crackdown on domestic dissent.
On one of the few remaining routes from Russia to the EU, trains from Saint Petersburg to Finland have been packed with Russians.
"I know some people who are quite desperate at the moment to go abroad," said Elena, a 37-year-old Russian living in Finland who did not want to give her full name.
A lot of people "don't feel safe, they know that the economic situation will be very hard from now on, and also many people from a moral perspective can't bear staying", she told AFP in Helsinki.
It is not just people fleeing.
Six lions and six tigers evacuated from a shelter near Kyiv arrived at a zoo in Poland, following a two-day odyssey skirting battle frontlines and coming face to face with Russian tanks.