The missiles were among the 30 launched at Ukraine a few hours before Ukrainian children began a third school year under the Russian invasion.

"Overnight, Russia fired a total of 35 missiles, including ballistic ones, and 23 drones at Ukraine," President Volodymyr Zelensky said.

Ukraine shot down nine ballistic missiles, 13 cruise missiles and 20 attack drones, the airforce said.

Loud explosions woke the capital up around 5:30 am (0230 GMT), according AFP journalists in Kyiv.

Debris from destroyed missiles fell in four districts and wounded three people, the head of the Kyiv military administration Sergiy Popko said.

Some of the wreckage damaged a mosque in Kyiv, said Zelensky, who accused Russia of "attempting to destroy all of our communities and even sacred places of worship."

As the war stretches into its third year, Ukrainians have seen daily aerial attacks on their country.

"Today's morning -- the morning the kids go back to school -- was no exception," Presidential aide Mykhaylo Podolyak said.

"Russia continues to deliberately attack civilians, critical infrastructure," he added.

A missile strike on the northeastern city of Sumy on Sunday evening damaged a social welfare centre and an orphanage, injuring 18 people including six children, the mayor Oleksandr Lysenko said on Telegram.

And shelling killed a woman in Kupyansk, regional governor Oleg Synegubov said.

Reacting to the latest missile attack, presidential chief of staff Andriy Yermak vowed a response to Russia's attacks.

"There will be an answer to everything. The enemy will feel it," Yermak posted on Telegram.

Kyiv has stepped up its strikes inside Russian territory, particularly since launching a ground offensive into the nearby Kursk region earlier this month.

Vyacheslav Gladkov, the governor of Russia's Belgorod region which borders Ukraine, said an overnight aerial attack by Ukrainian forces wounded one person and damaged a shop and an infrastructure facility in the eponymous capital Belgorod.