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.

Russia launched 550 drones and missiles across Ukraine overnight in the largest aerial assault since the war began. The capital Kyiv was the primary target.

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.