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 traveling, killing the 39-year-old woman and 40-year-old man on the spot, it said.

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.

Russia's Defence Ministry, in a report on Telegram, said air defence units had destroyed 48 Ukrainian drones in a period of just over five hours into Saturday evening. Those included five drones in the region surrounding Moscow, two of which were headed for the capital.