At least 44 others were wounded in strikes that hollowed out a residential building and destroyed dozens of apartments.
Emergency workers were at the scene to rescue people from under the rubble.
Ukraine’s interior minister, Ihor Klymenko, said 27 locations across the capital have been hit – including educational institutions and critical infrastructure.
Explosions were heard throughout the night – and Mr Klymenko says a US citizen is among those killed.
It comes as the G7 Summit in Canada continues, which Ukraine’s leader is expected to attend.
Volodymyr Zelenskyy was due to hold talks with Donald Trump – but the US president has announced he is unexpectedly returning to Washington because of tensions in the Middle East.
Moscow has launched a record number of drones and missiles in recent weeks, and says the attacks are in retaliation for a Ukrainian operation that targeted warplanes in airbases deep within Russian territory.
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