At least six people were killed and more than 50 others injured after a barrage of Russian drones and missiles struck Kyiv overnight, Ukrainian officials said.
One of the dead includes a six-year-old boy, while three other fatalities were confirmed at the site of an apartment block which collapsed following a strike.
Tymur Tkachenko, head of Kyiv's military administration, said the death toll could rise, with damage in more than two dozen locations across the Ukrainian capital.
Russian attacks have continued despite US President Donald Trump's threat to impose tougher sanctions on Moscow if Russian leader Vladimir Putin does not agree to a ceasefire by 8 August.
Igor Klymenko, Ukraine's interior minister, said: "One of the strikes hit a residential high-rise building, an entire entrance was destroyed. Rescuers are clearing the rubble."
