The casualties numbers were likely to rise, Kyiv City Military Administration head Tymur Tkachenko said on Thursday.
A large part of a nine-storey residential building collapsed after it was struck, he said.
Rescue teams were at the scene to search for people trapped under the rubble.
Russia fired 309 Shahed and decoy drones, and eight Iskander-K cruise missiles overnight, the Ukrainian air force said.
Ukrainian air defences intercepted and jammed 288 strike drones and three missiles, with five missiles and 21 drones striking targets.
Russia's defence ministry, meanwhile, said its forces took full control of the strategically important city of Chasiv Yar in Ukraine's eastern Donetsk region.
Ukrainian officials, who typically do not confirm retreats, did not immediately comment.
Russian and Ukrainian troops have battled for control of Chasiv Yar for nearly 18 months.
It includes a hilltop from which troops can attack other key points in the region that form the backbone of Ukraine's eastern defences.
A report on Thursday from Ukraine's Army General Staff said there were seven clashes in Chasiv Yar in the past 24 hours.
An attached map showed most of the town as being under Russian control.
DeepState, an open-source Ukrainian map widely used by the military and analysts, showed early on Thursday that neighbourhoods to the south and west of Chasiv Yar remained as so-called grey zones, or uncontrolled by either side.
The attack targeted the Kyiv, Dnipro, Poltava, Sumy, Mykolaiv regions, with Ukraine's capital being the primary target, President Volodymyr Zelenskiy wrote on Telegram.
"Today, the world once again saw Russia's answer to our desire for peace with America and Europe," Zelenskiy said.
"New demonstrative killings. That is why peace without strength is impossible."
He called on Ukraine's allies to follow through on defence commitments and pressure Moscow towards real negotiations.
Plumes of smoke emanating from a partially damaged building and debris strewn on the ground.
At least 27 locations across Kyiv were hit by the attack, Tkachenko said, with the heaviest damage seen in the Solomianskyi and Sviatoshynskyi districts.
US President Donald Trump said Tuesday that he's giving Russian President Vladimir Putin a shorter deadline - August 8 - for peace efforts to make progress, or Washington will impose punitive sanctions and tariffs.
Western leaders have accused Putin of dragging his feet in US-led peace efforts in an attempt to capture more Ukrainian land.
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