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.

KYIV, Ukraine -- Russia targeted Ukraine overnight with 322 drones, 292 of which were "neutralized" by being either shot down or supressed by other means, according to the Ukrainian air force. Eleven people, including two children, were injured in the Kharkiv area, in a drone strike overnight there, according to local emergency services.