Ukrainian authorities issued an alert for a missile attack, and AFP journalists heard explosions across the capital.

"Russia has launched a massive combined strike on Kyiv," Ukraine's state emergency service said on Telegram, updating the toll.

"According to preliminary data, nine people were killed, 63 injured," it said, adding that among the 42 people hospitalised, six were children.

Five districts across the capital suffered damage, including fires in garages and administrative buildings that have been extinguished.

The state emergency service said the attack also damaged residential buildings.

"The search for people under the rubble is underway," it said.

In a bomb shelter set up in a basement of a residential building, over a dozen residents gathered after the air alert started, an AFP journalist witnessed.

Kyiv was last hit by missiles in early April when at least three people were wounded.

It has been the target of sporadic attacks since Russia launched its full-scale invasion in February 2022.

In Ukraine's east, the city of Kharkiv was hit by seven missiles early Thursday, city mayor Igor Terekhov said, adding later that it was "under attack by cruise missiles for the second time in one night".

"One of the most recent strikes hit a densely populated residential area... Two people were injured there. The inspection of the sites of enemy strikes is underway," Terekhov said, urging the city's residents to "be careful".

Andriy Yermak, a top aide to Ukraine's President Volodymyr Zelensky, said Russia was attacking Kyiv, Kharkiv and other cities "with missiles and drones right now".

"Putin shows only a desire to kill," he said. "The attacks on civilians must stop."