Moscow targeted regions across Ukraine with some 101 drones, Zelenskyy said. Russia on Friday had launched its largest overnight strike of the war, firing 539 drones and around a dozen missiles, according to Ukraine's air force.

Ukraine said it struck a Russian air base on Saturday, while Russia continued to attack Ukraine with hundreds of drones overnight as part of a stepped-up bombing campaign that has dashed hopes for a breakthrough in efforts to end the more than 3-year-old war.

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.