“According to preliminary information, there were injuries among the servicemen undergoing treatment in the medical centre,” the military’s general staff said on the Telegram messaging app.

Kharkiv mayor Ihor Terekhov said one of the dead had been pulled out from under rubble.

He put the overall number of injured at 27.

He said an office building was also among the targets, with one drone triggering a fire.

Oleh Syniehubov, the regional governor, said 25 people were hurt, while prosecutors, quoted by public broadcaster Suspilne, put the number at 30.

Suspilne posted photos of rescue teams in protective equipment sifting through rubble as well as piles of twisted metal and construction materials outside buildings.

Kharkiv, located in northeastern Ukraine, resisted capture in the early weeks of Russia’s February 2022 invasion.

But as Russian forces focused their attention on capturing large swathes of eastern Ukraine, the city has been a frequent target of air attacks.