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.

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,