Ukrainian drones attacked a drone development facility in Dubna, a city in the Moscow Oblast, according to Russian Telegram channels Astra and Baza citing local residents.

Social media videos show drones flying over Dubna and explosions with fires after impact. Local residents in the footage say "Kronshtadt got hit again."

Moscow Mayor Sergei Sobyanin posted 17 messages about drone attacks since the start of the day. He said air defenses destroyed at least 31 drones heading toward the Russian capital.

Sobyanin also reported repelling drone attacks on Zelenograd. The official said that both Moscow and Zelenograd had "no serious damage or casualties" and that "emergency services specialists are working at the debris impact sites."

Dubna is known as a "science city." The city sits 121 kilometers north of Moscow in the Moscow Oblast.

Russia's Defense Ministry later claimed that from 9 pm on 27 May to 7 am on 28 May, air defenses allegedly destroyed and intercepted 296 Ukrainian drones over Moscow region and 12 other Russian oblasts including Bryansk, Belgorod, Vladimir, Voronezh, Ivanovo, Kaluga, Kursk, Orel, Ryazan, Smolensk, Tver and Tula.

The Russian defense ministry reported neither the total number of drones allegedly flying toward Russian territory nor the consequences of attacks.

Earlier, Moscow's mayor announced drone attacks on Russia's capital. Moscow and other Russian airports suspended operations during the incident.

The Russian Defense Ministry previously claimed that on the evening of 27 May, from 9 pm to midnight Moscow time, their air defenses allegedly intercepted and destroyed 112 Ukrainian drones.

Ukraine has been conducting an air campaign against Russian strategic targets such as ammunition depots, command centers, military factories, oil processing and storage facilities, but rarely comments of the attacks.