Ukrainian President Volodymyr Zelensky has said the death toll from Russian drone and missile strikes on the capital Kyiv has risen to five, with around 40 others wounded.
Officials said Russia pummeled Kyiv and several other regions in a massive aerial attack.
The first combined missile and drone barrage since the end of a brief US-brokered ceasefire came hours after Moscow unleashed hundreds of drones in a daytime attack that killed six.
"As of now, already 5 people have been reported killed in Kyiv as a result of last night's Russian attack," Mr Zelensky wrote in a statement on social media, adding: "There must be a just response to all these strikes."
Prime Minister Yuliia Svyrydenko said the overnight strike targeted civilian infrastructure and residential buildings.
Images posted by the State Emergency Service showed rescuers digging through the rubble of a collapsed apartment building in search of survivors.
Mayor Vitalii Klitschko said 11 people had already been rescued.
Mr Zelensky said Russia had launched more than 670 attack drones and 56 missiles in the attack that homed in on targets mainly in Kyiv.
"These are definitely not the actions of those who believe the war is coming to an end. It is important that partners do not remain silent about this strike," he wrote on social media, warning that more people could be trapped under the rubble at strike sites.
The Ukrainian leader added that more than 20 locations in Kyiv had been damaged, including residential buildings, a school, a vet and other civilian infrastructure.
Tymur Tkachenko, the head of Kyiv's military administration, said one person was killed and 16 others were wounded in the barrage on the city.
Ukraine's state emergency service later reported 31 people, including a child, had been wounded in strikes across the Kyiv region.
Ukrainian Foreign Minister Andrii Sybiha said the attack during US President Donald Trump's visit to China showed Russia wants to continue fighting despite a peace push by Washington.
"There should be no illusions or wishful thinking: only pressure on Moscow can force him to stop," he wrote on social media.
"I am certain that the leaders of the United States and China have enough leverage over Moscow to tell Putin to finally end the war."
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The overnight strike also targeted railway infrastructure and ports in the southern Odesa region, said Deputy Prime Minister Oleksiy Kuleba.
The Ukrainian Air Force said Russia's barrage included 675 drones and 56 missiles, most of which were downed by air defences.
It said 38 hits had been recorded across 24 locations.
Fighting between Russia and Ukraine has dragged into its fifth year despite the US-backed peace effort that has sputtered and produced few concrete results
