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.
"We do not have any conclusive evidence at the moment as to who launched this missile ... it was most likely a Russian-made missile, but this is all still under investigation at the moment," Andrzej Duda, preident of Poland, told reporters. The Polish foreign ministry had earlier said that a Russian-made rocket had fallen on the village.
Mr Duda said that it was very likely that Poland would request consultations under Article 4 of the Nato military alliance following the blast. "Our ambassador will be attending the meeting of the North Atlantic Council tomorrow at 10 am at Nato headquarters ... it is highly likely that the ambassador will request the activation of Article 4, or allied consultations," he said.
Mr Duda spoke after Mr Morawiecki said that Poland would increase surveillance of its airspace following the incident.
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.
LATEST NEWS: Over 100 missiles fired in heaviest airstrikes of war
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.
In the capital Kyiv, flames funnelled out of a five-storey apartment block, one of two residential buildings the authorities said had been hit there. The mayor said one person was confirmed killed and half the capital left without power. Residents were urged to stay indoors.
“The danger has not passed,” said Kyrylo Tymoshenko, the deputy head of President Zelensky’s office, as the country’s grid operator Ukrenergo said emergency outages were being enforced in response to attacks.
Other strikes or explosions were reported in cities ranging from Lviv and Zhytomyr in the west to Kryvyi Rih in the south and Kharkiv in the east. Regional officials reported some of the attacks had knocked out electricity supplies.
The mayor of Lviv said power was down in the city and the mayor of Kharkiv, Ihor Terekhov, said critical infrastructure facilities had been damaged.
Hours earlier, the Ukrainian president had called on world leaders at the G20 summit in Indonesia to help bring an end to Vladimir Putin’s invasion.
The war was a focus of the G20 summit, where Western leaders denounced Moscow.
Western countries sought a summit declaration that would condemn the war despite Russian opposition and a lack of unanimity.
Diplomats circulated a 16-page draft that said: “Most members strongly condemned the war in Ukraine and stressed it is causing immense human suffering and exacerbating existing fragilities in the global economy.”
France’s president Emmanuel Macron also called on China to cooperate more closely to help end the war. China is seen as a key Russian ally for the conflict, but in September it emerged that Beijing had “questions and concerns” about the conflict.
However, a Chinese summary of the talks with Mr Macron made no mention of Ukraine until the final paragraph.
The Kremlin’s foreign minister Sergey Lavrov, head of Russia’s delegation in Mr Putin’s absence, accused the West of trying to politicise the declaration.
Also on Tuesday, the United Nations Commission on Human Rights (UNCHR) found that both Russia and Ukraine have tortured prisoners of war.
The Ukraine-based monitoring team based its findings on interviews with more than 100 prisoners of war on each side of the conflict.
