Volodymyr Zelensky said Russian missiles hit Nato member Poland on Tuesday in what he called a “significant escalation” of the conflict as dozens more caused destruction and power outages across Ukraine.
US and other western officials were investigating explosions at a grain store in Przewodow, Lublin, in which two people were killed.
Polish prime minister Mateusz Morawiecki called an urgent meeting of the country’s security and defence councils.
Pictures from the scene showed a huge crater in the ground but the Pentagon said it had no information to corroborate reports of Russian involvement.
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But Ukraine’s president said Moscow was to blame.
“Russian missiles hit Poland,” he said. “The longer Russia feels impunity, the more threats there will be to anyone within reach of Russian missiles.
“To fire missiles at Nato territory! This is a Russian missile attack on collective security! This is a very significant escalation. We must act.
Mr Zelensky’s adviser Mykhailo Podolyak said that the strikes on territory were not an accident, but a deliberately planned “hello” from Russian forces.
“It happens when evil goes unpunished and politicians engage in “pacification of aggressor” he said. He added that Moscow had “disguised whatever happened as a a “mistake”.
Latvia’s defence minister Artis Pabriks meanwhile said that Naro could provide additional anti-aircraft defence to Poland and “a part of the territory of Ukraine”.
He had earlier tweeted condolences “to our Polish brothers in arms”, and said: “Latvia fully stands with Polish friends and condemns this crime.”
Officials from Norway, Lithuania and Estonia – that are all members of the Nato defence alliance – said they were trying to find out more information. “This is a very serious incident but much remains unclear,” Norwegian foreign minister Anniken Huitfeldt said, according to Norwegian news agency NTB.
Russia denied the reports and said that Polish media and officials were deliberately trying to escalate tensions.
Meanwhile, Ukrainian officials said that Moscow fired some 90 missiles at Ukraine, causing widespread power outages across the country, leaving the capital Kyiv without electricity and leaving at least one person dead.
The missiles hit several other cities including Lviv and Zhytomyr in the west, Kryvyi Rih in the south and Kharkiv in the east. Several residential areas were reportedly hit. There were also claims the missiles had caused power cuts in neighbouring Moldova.
A Ukrainian air force spokesperson said Russia fired around 100 missiles, while President Zelensky put the number at 90 but warned more could follow.
“I want to say now to all our Polish brothers and sisters: Ukraine will always support you,” he added.
The barrage came just days after Russian troops retreated from the key southern city of Kherson and followed a pattern in recent weeks of Moscow lashing out far from the front after battlefield losses.
