Russian ballistic missiles killed 12 people and injured more than 30 in Kyiv early on Thursday, authorities said, damaging buildings and severing power supply to some parts of the Ukrainian capital.
A fire broke out and the upper floors of a nine-storey residential block were destroyed in the city's Solomianskyi district, where seven people were killed, Mayor Vitali Klitschko said, calling for Friday to be observed as a day of mourning.
Two other districts also suffered damage, Klitschko said on the Telegram messaging app, with non-residential facilities, warehouses, a school and a children's hospital hit.
Power company DTEK said it restored electricity to more than half of the roughly 90,000 homes left without power in the capital following the attack.
The attack came as Russia and Ukraine have significantly stepped up long-range attacks deep behind each other's lines, pushing the civilian death toll to its highest levels since the conflict's first months in 2022.
It also came two days after Moscow suffered its largest Ukrainian drone attack in two years, with 620 unmanned aerial vehicles (UAVs) targeting the Russian capital, according to local authorities.
The Russian defense ministry said Moscow attacked Kyiv and the surrounding region with airstrikes and drones, hitting facilities producing drone components, a military depot and a logistics hub, as well as other targets.
Explosions rip through the city
A Reuters witness reported hearing more than a dozen explosions. In the region around the Ukrainian capital, another person was killed, an official said on Telegram.
Ukraine's emergency service showed video of servicemen battling a blaze in a building and helping people to escape facilities destroyed during the night in Kyiv.
Ukraine has also increased its attacks on Russia, targeting oil facilities and logistics infrastructure to try to undermine Moscow's military capability.
Diplomatic efforts have failed so far to yield a lasting ceasefire in the conflict, which started with Russia's military operation in Ukraine in February 2022.
A drone crashed into NATO and European Union member Romania during the Russian attack on Ukraine, the Romanian defense ministry said on Thursday. A drone also crossed Moldova's airspace, the country's military said.
Ukraine handed proposals to US negotiators, Steve Witkoff and Jared Kushner, for a plan to end the conflict, President Volodymyr Zelenskyy said this month, and he has also repeatedly asked for interceptor missiles to ward off missile attacks.
Russia did not receive specific proposals for possible new meetings with US negotiators, foreign ministry spokeswoman Maria Zakharova told the Izvestia newspaper, but added that Moscow would be ready to arrange a meeting at short notice.
(With input from Reuters)
