Russia bombarded Ukraine’s second-largest city with massive strikes in the early hours of Saturday, its mayor said, one night after Moscow carried out one of the war’s largest aerial assaults on Ukraine.

Photos showed burnt and partially destroyed houses and vehicles, and rescuers carrying the injured to safety and removing debris.

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.