The Russians were assembling UAVs in workshops of the Kaluga Aerated Concrete plant, according to the sources. Locals reported powerful explosions and a fire at the factory overnight into March 13. Kaluga social media channels mentioned alleged debris falls and a blaze in “industrial enterprise buildings.

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,

Ukrainian long-range drones attacked a UAV production site in the village of Obukhovo, Dzerzhinsk district, Kaluga region, Russia.