Ukrainian military intelligence drones (HUR) attacked a camouflaged drone production facility in Kaluga Oblast late on March 12, HUR sources confirmed for the Kyiv Independent.
Drone production lines were located on the grounds of an aerated concrete plant in the village of Obukhovo in Kaluga Oblast's Dzerzhinsky district, one of the sources claimed.
Kyiv has carried out regular long-range drone strikes against military and industrial facilities in Russia's rear, seeking to undermine its ability to wage its all-out war.
The statement comes after Kaluga Oblast Governor Vladislav Shapsha said that 25 drones were downed over the region overnight, with drone wreckage setting fire to an unspecified industrial facility in Dzerzhinsky district.
One employee suffered minor injuries, and the fire has been extinguished, according to Shapsha.
Locals reported powerful explosions and a fire at the plant on social media. Drone debris also damaged a cell tower and a power line in the Khvastovichsky district, the southernmost part of Kaluga Oblast, Shapsha said.
Russian air defenses downed 77 drones overnight, including 30 over Bryansk Oblast, six over Kursk and Voronezh oblasts each, and five over Rostov and Belgorod oblasts each, the Russian Defense Ministry claimed.
An unspecified infrastructure facility was also damaged on the evening of March 12 in Voronezh Oblast, a region bordering Ukraine's Luhansk Oblast, Governor Alexander Gusev said on his Telegram channel.
The targeted facility was part of the region's gas infrastructure, the Baza Telegram channel reported, citing residents.
The Kyiv Independent could not verify the claims.
Airports in Penza, Saratov, and Volgograd imposed temporary flight restrictions overnight, Russia's Federal Air Transport Agency announced.
Martin Fornusek
