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.

Several regions in Russia were rocked by explosions overnight on March 9 as air defense systems responded to incoming drones. Reports indicate that a factory, an industrial plant, and an oil facility in the Ryazan, Lipetsk, Voronezh, and Kursk regions came under attack.

Drone production lines were located on the grounds of an aerated concrete plant in the village of Obukhovo in Kaluga Oblast's Dzerzhinsky district, a military intelligence source claimed.