Drones have hit high-rise buildings in Kazan, the capital of Russia's republic of Tatarstan, with the attacks causing the city's airport to temporarily suspend flights. The Russian Defense Ministry said the attacks came in three waves between 7:40 a.m. and 9:20 a.m. local time on December 21. The ministry claimed the drones were of Ukrainian origin, while Ukrainian authorities have not issued any comment. The press service of Rustam Minnikhanov, the leader of the autonomous republic of Tatarstan, said in a statement that eight drones attacked the city.