KYIV, Ukraine (AP) — Russia fired more than 100 drones at civilian areas of Ukraine overnight, authorities said Monday, as the Kremlin dismissed its transportation chief after a weekend of travel chaos when airports grounded hundreds of flights during the busy vacation season due to the threat of attacks from Kyiv.

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

Russian air defences shot down four Ukrainian drones headed for Moscow on Saturday, the city's mayor said, while one of the capital's main airports temporarily halted outgoing flights. Mayor Sergei Sobyanin said emergency services were working at the sites of the downed drones,