A fire broke out after Russia attacked the upper floors of a nine-storey residential building, Klitschko said, and people were trapped in another place as Moscow hit non-residential and apartment facilities, warehouses and a children's hospital.
In the Solomianskyi district, debris fell near a residential building, blowing out windows and causing a fire, Klitschko said on Telegram.
A Reuters witness reported hearing more than a dozen explosions. In the region surrounding the Ukrainian capital, another person was killed, a local official said separately on Telegram.
Separately, attacks on shipping have shut down more than 97 per cent of Russia and Ukraine's grain export capacity in the Azov and Black Sea basin, cutting off a major source of low-cost supplies and helping to drive up global prices.
The two major grain exporters have intensified attacks on ports and shipping over the past month, leaving importers in the Middle East, Africa and Asia facing the prospect of sourcing grain from higher-cost suppliers such as Australia and the United States.
Russia and Ukraine together exported an average of 7.2 million metric tonnes of grain a month from terminals in the Azov and Black Sea region last season, according to Reuters calculations based on official data and analyst estimates.
There are no shipments from Ukraine's Black Sea terminals. In Russia, the only grain terminal not officially shut is a small facility in Tuapse with a capacity of about 160,000 tonnes per month, officials and trade sources say.
The shutdowns represent a loss of more than 97 per cent of grain export capacity compared with last season, Reuters calculations show.
"At present, civilian shipping in the Black Sea has virtually ground to a halt," said Yevgeny Karabanov, head of the analytical committee of the Grain Union of Kazakhstan, which also ships grain through Russian ports.
Global wheat prices have risen about 6.5 per cent this month and are now roughly 30 per cent higher than a year ago.
While large stockpiles and stronger harvests have allowed importers to delay purchases, traders say pressure is mounting to secure supplies because there are no signs of de-escalation in the Black Sea region.
Several carriers loading or preparing to load grain at Russian ports were hit by drones this week, sources said.
Analysts at Rusagrotrans, part of Demetra Holding, estimate Russia's August wheat exports at 1.8 million tonnes, the lowest level for the month since 2010.
Trade sources said major Russian grain terminals in Novorossiysk, including NZT and NKHP, were shut after a Ukrainian drone strike.
KSK, Russia's largest grain terminal, suspended grain deliveries and exports while operations at the Taman grain terminal were also halted.
Ukrainian seaports in the Odesa port hub effectively ceased operations at the end of July.
As of mid-August, no new ship calls had been recorded, Agriculture Minister Taras Vysotskyi said last week.
Ukraine is exporting grain through rail links with Eastern Europe and Danube river ports, each accounting for about 45 per cent of shipments, with the remaining 10 per cent transported by road.
"We expect that we will be able to reach 50 per cent of our export potential if the ports remain blocked," Vysotskyi said.
Russia can redirect some exports through Baltic, Caspian and Far Eastern ports, though longer transport distances are likely to create logistical challenges and increase costs.
