At least three people have been killed and another 17 injured in the biggest Russian drone attack on Ukraine's second-largest city of Kharkiv, the mayor says.

Ihor Terekhov says that overnight Russia launched 48 drones, as well as two missiles and four gliding bombs.

"We have a lot of damage," he says, adding that three high-rising residential buildings were hit. Footage has emerged showing several storeys of one such building on fire.

Six people were killed and 80 injured across Ukraine the previous night, when Russia attacked the country with more than 400 drones and nearly 40 missiles.

Russia said that aerial attack was in response to "terrorist acts by the Kyiv regime", claiming that military sites were targeted.