By Pavel Polityuk and Aleksandar Vasovic
LVIV, Ukraine/KYIV (Reuters)—Russian invasion forces seized Europe's biggest nuclear power plant on Friday in what Washington called a reckless assault that risked catastrophe, although a blaze in a training building was extinguished and officials said the facility was now safe.
Combat raged elsewhere in Ukraine as Russian forces surrounded and bombarded several cities in the second week of the assault launched by Russian president Vladimir Putin.
A presidential adviser said an advance had been halted on the southern city of Mykolayiv after local authorities said Russian troops had entered it. If captured, the city of 500,000 people would be the biggest yet to fall.
The capital Kyiv, in the path of a Russian armoured column that has been stalled on a road for days, came under renewed attack, with air raid sirens blaring in the morning and explosions audible from the city centre.
The Russian assault on the Zaporizhzhia plant showed how reckless the invasion has been, U.S. Pentagon spokesman John Kirby told CNN.
"It just raises the level of potential catastrophe to a level that nobody wants to see," Kirby said.
A video verified by Reuters showed one building aflame and a volley of incoming shells before a large incandescent ball lit up the sky, exploding beside a car park and sending smoke billowing across the compound.
Although the plant was later said to be safe and the fire out, officials worried about the precarious circumstances, with Ukrainian staff now operating under Russian control.
International Atomic Energy Agency chief Raphael Grossi described the situation as "normal operations, but in fact there is nothing normal about this."
He paid homage to the plant's Ukrainian staff: "to their bravery, to their courage, to their resilience because they are doing this in very difficult circumstances."
Grossi said the plant was undamaged from what he believed was a Russian projectile. Only one reactor was working, at around 60% of capacity. He was trying to contact Russian and Ukrainian officials to sort out political responsibility.
An official at Energoatom, the Ukrainian state nuclear plant operator, said there was no further fighting and radiation was normal, but his organization no longer had contact with the plant's management or control over potentially dangerous nuclear material.
"Personnel are on their working places providing normal operation of the station," the official told Reuters.
Russia's defense ministry also said the plant was working normally. It blamed the fire on a "monstrous attack" by Ukrainian saboteurs and said its forces were in control.
"EUROPEANS WAKE UP"
Russia's grip on a plant that provides more than a fifth of Ukraine's electricity was a big development after eight days of war in which other Russian advances have been stalled by fierce resistance.
"Europeans, please wake up. Tell your politicians—Russian troops are shooting at a nuclear power plant in Ukraine," Ukrainian president Volodymyr Zelenskiy said in a video address. In another address, he called on Russians to protest.
Thousands of people are believed to have been killed or wounded and more than 1 million refugees have fled Ukraine since Feb. 24, when Putin ordered the biggest attack on a European state since World War Two.
Russian forces advancing from three directions have besieged cities, pounding them with artillery and air strikes.
Moscow says its aim is to disarm its neighbour and capture leaders it calls neo-Nazis and a threat to its own security. Ukraine and its Western allies call that a baseless pretext for a war to conquer a country of 44 million people.
FIGHTING RAGES, SANCTIONS MOUNT
In Kyiv's Borshchahivka neighbourhood, the twisted engine of a cruise missile lay in the street where it had apparently been downed overnight by Ukrainian air defences.
Residents were furious but also proud of what they see as the successful defense of the city of 3 million, which Russia had hoped to capture within days.
Russian troops "all should go to hell," said Igor Leonidovich, 62, an ethnic Russian who had moved to Ukraine 50 years ago as a boy. "For the occupiers it is getting worse and worse, every day."
In Russia itself, where Putin's main opponents have largely been jailed or driven into exile, the war has led to a further crackdown on dissent. Authorities have banned reports that refer to the "special military operation" as a "war" or "invasion." Anti-war demonstrations have been squelched with thousands of arrests.
On Friday, Russia shut down foreign broadcasters including the BBC, Voice of America, and Deutsche Welle. The most prominent independent Russian broadcasters, TV Dozhd (Rain) and Ekho Moskvy radio, were shuttered on Thursday. The lower house of parliament introduced legislation to impose jail terms on people who spread "fake" reports about the military.
Russia has been subjected to economic isolation never before visited on such a large economy. Ireland's foreign minister, Simon Coveney, said more EU sanctions were coming, potentially including a ban on Russian-flagged ships in European ports and blocking imports of steel, timber, aluminium or coal.
British foreign secretary Liz Truss said Western countries should look at measures targeting Russia's oil and gas sector—still excluded from sanctions—and how how reduce their dependence on Russian energy.
Only one sizeable Ukrainian city, the southern port of Kherson, has fallen to Russian forces since the invasion began.
But Russian forces have made their biggest advances in the south. Mykolayiv's mayor said they were now inside his city, a shipbuilding port of 500,000 people.
Zelenskiy's military adviser, Oleksiy Arestovych, said the Russian advance there had been halted.
"We can feel cautious optimism about the future prospects of the enemy offensive – I think that it will be stopped in other areas also."
The southeastern port of Mariupol has been encircled and bomabarded, Britain said in an intelligence update. Authorities there have described a humanitarian emergency.
In the northeast, along another axis of the Russian attack, Kharkiv and Chernihiv have been under bombardment since the start of the invasion. Strikes have intensified but defenders are holding out.
On Thursday, Russia and Ukraine negotiators agreed at talks on the need for humanitarian corridors to help civilians escape and to deliver medicines and food to areas of fighting.
A spokesperson for the United Nations childrens' agency in Lviv said there had been an "insane influx" of people into the city. Pediatricians were preparing for mass child casualties and identifying them, James Elder said.
"A green dot means fine over here, a yellow dot means critical support. They are learning a black dot means the child won't make it."
(Reporting by Pavel Polityuk, Natalia Zinets, Aleksandar Vasovic in Ukraine, John Irish in Paris, Francois Murphy in Vienna, David Ljunggren in Ottawa, and other Reuters bureaux. Writing by Lincoln Feast and Peter Graff. Editing by Timothy Heritage and Angus MacSwan.)