Ukraine and Russia traded blame for a deadly missile strike on Saturday that killed at least four people in the dormitory of a boarding school situated in a part of Russia's Kursk region held by Kyiv forces.

The Ukrainian army said four people were killed and dozens - many of them elderly - were injured in the town of Sudzha in the Kursk region, which has been under Ukrainian control for five months. More than 80 people are reported to have been rescued from the building.

Russia fired a barrage of drones and missiles at Ukraine on Saturday, killing 12 people and blasting its energy grid, officials said.