Moscow said Thursday it had downed multiple Ukrainian drones overnight in annexed Crimea and the Black Sea, as well as in parts of western Russia.
"Air defense systems destroyed 19 Ukrainian drones over the Black Sea and the territory of the Republic of Crimea," the Russian Defense Ministry said on the messaging app Telegram.
Mikhail Razvozhayev, the Kremlin-installed governor of Sevastopol, denied that several drones were destroyed near the city, which is home to Russia's Black Sea fleet.
"Yes, air defense is working, but in the area of Crimea," he wrote on Telegram, referring to the rest of the peninsula, which is governed separately from the city.
"In Sevastopol, all services are on alert, and the air situation is being monitored," Razvozhayev added.
Oleg Kryuchkov, adviser to the Kremlin-installed governor of annexed Crimea Sergei Aksyonov, asked residents "to remain calm."
"If you hear the sounds of a drone flying by or air defense systems, move away from the windows. Official information will come later," Kryuchkov said on Telegram.
Meanwhile, Russia's Defense Ministry reported three drone attacks had been "thwarted" in the Kursk, Belgorod and Oryol regions, all of which are located in the western part of Russia.
Since Ukraine launched its counteroffensive in early June, Russia has faced mounting waves of drone attacks.
Russian officials have sought to downplay their significance.