KYIV, Ukraine — Russia fired more than 100 drones at civilian areas of Ukraine overnight, authorities said Monday, as the Kremlin dismissed the country’s transport chief after a weekend of travel chaos when Russian airports grounded hundreds of flights due to the threat of Ukrainian drone attacks.

Russia and Ukraine have exchanged hundreds of drone strikes, causing several deaths and significant disruptions

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.