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.

Hundreds of flights were delayed or canceled due to Ukrainian drone strikes on Saturday and overnight, according to Russia’s Transport Ministry.

Ukraine launched a drone attack on the Sergiyev Posad district near Moscow early on Friday, injuring one person and damaging power infrastructure, the head of the district said. "I ask everyone to remain calm,