Hours later, Russia launched a glide bomb and a drone at the front-line town of Kostyantynivka in eastern Ukraine, killing four civilians and injuring a fifth, the prosecutor’s office said. The drone struck a car in which a married couple were travelling, killing the 39-year-old woman and 40-year-old man on the spot, it said.

Ukraine said Saturday it struck an airbase in Russia, which continued overnight to use hundreds of drones in its stepped-up bombing campaign. The fresh wave of attacks signal a breakthrough isn't expected anytime soon in efforts to end the more than three-year-old war.

At least three children were among 20 people wounded as a result of a Russian drone attack on Ukraine's second-largest city of Kharkiv overnight that damaged apartments and a kindergarten, Ukrainian authorities said this morning. A fire broke out in a multi-storey residential building in Kharkiv as a result of the attack, mayor Ihor Terekhov said.