Russia attacked the eastern Ukrainian city of Kharkiv at night and in the evening with drones, missiles and guided bombs, killing at least four people and injuring more than 60, including a baby, local officials said on Saturday.

Air assaults on Saturday killed at least four people. Kharkiv’s mayor described an overnight strike as “the most powerful attack” since the beginning of the war.

Russia claims Ukraine indefinitely postponed the release while Kyiv maintains it has been delayed until next week.