Kyiv has accused Moscow's forces of killing civilians in attacks on cities in eastern and southern Ukraine, as the country's president and the head of the US Central Intelligence Agency warned that the Kremlin could use tactical nuclear weapons during the conflict.
Officials in Ukraine’s second city, Kharkiv, said seven people were killed and 34 injured in an artillery strike on a residential area on Friday, a day after they said seven people were killed and 27 hurt when Russian troops fired on two minibuses that were evacuating civilians in the Kharkiv region.
In the southern city of Mykolaiv, regional governor Vitaliy Kim said five people were killed and 15 injured on Friday when "cluster munition" hit a residential area.
The reports could not be confirmed, but Ukraine and its western allies say Russian forces are repositioning to launch a major assault on the eastern Donbas region after being beaten back from areas around the capital, Kyiv.
Russia says it has taken control of the strategic Azov Sea port of Mariupol, but Ukraine insisted on Friday that some industrial areas of the Donbas city were still being defended by government forces, despite a month-long siege and massive bombardment that Ukrainian officials believe may have killed 20,000 civilians.
"The situation in Mariupol is difficult and hard. Fighting is happening right now. The Russian army is constantly calling on additional units to storm the city. But as of now the Russians haven't managed to completely capture it," said Ukrainian defence ministry spokesman Oleksandr Motuzyanyk.
Long-range bombers
He also said Russia had fired on Mariupol from long-range bombers, the first time they had been used during seven weeks of all-out war between the neighbours, as it sought to establish control over a territory linking Russia with the annexed Crimean peninsula.
Some Ukrainian and western officials have warned that Russian president Vladimir Putin may try to escalate the conflict – potentially using chemical or nuclear weapons or seeking to involve Nato states – if his forces continue to suffer heavy losses in Ukraine.
"Not only me – all of the world, all of the countries, have to be worried," Ukrainian president Volodymyr Zelenskiy told CNN in an interview aired on Friday, when asked about the threat of Russian nuclear and chemical weapons.
“Chemical weapons…they could do it, for them the life of the people – it’s nothing.”
In a speech at Georgia Tech university on Thursday, CIA director William Burns said: "Given the potential desperation of President Putin and the Russian leadership, given the setbacks that they've faced so far, militarily, none of us can take lightly the threat posed by a potential resort to tactical nuclear weapons or low-yield nuclear weapons."
Moscow warned Sweden and Finland this week that they would have to reckon with "the most undesirable consequences" and the prospect of hypersonic and nuclear-capable Russian missiles being stationed in the Baltic region if they decided to join Nato.
All-out invasion
Both Nordic states are now considering whether to apply to join the alliance in the coming months in response to Russia’s all-out invasion of Ukraine.
"At this point I can say that it is highly likely, but the decision is not yet made," said Finland's European affairs minister Tytti Tuppurainen.
“The people of Finland, they seem to have already made up their mind and there is a huge majority for the Nato membership,” she told Sky News.
Russia's war on Ukraine is believed to have killed thousands of civilians and displaced more than 10 million people – five million of whom have fled Ukraine, the United Nations refugee agency said on Friday.
The invasion has also shredded relations between Russia and the West, and on Friday Moscow expelled 18 members of the European Union delegation in the city, in apparent retaliation for Brussels ordering 19 Russian diplomats to leave last week.