Russia launched a new barrage of missiles at Ukraine on Friday and air defence systems went into operation across the country, Ukrainian officials said.
Explosions were heard in the eastern city of Kharkiv. Locals officials said critical infrastructure had been hit there and in the Black Sea region of Odesa.
Reuters witnesses heard explosions in the capital Kyiv. It was not immediately clear if any were caused by missiles getting through air defences.
There was no immediate word of casualties and it was not clear what critical infrastructure had been hit.
"Do not ignore air raid alerts, remain in shelters," Kyrylo Tymoshenko, deputy head of the president's office said on the Telegram messaging app.
As many as 60 Russian missiles had been spotted heading for Ukraine, said Vitaly Kim, who is the governor of the Mykolaiv region in southern Ukraine.
Russia has carried out several waves of attacks on Ukrainian energy infrastructure since October, causing power outages across the country.
The governor of the northern region of Sumy said there were power outages in his region because of Friday's missile strikes.
More details to follow.
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