Ukrainian drones targeted industrial infrastructure in Russia's Volgograd region, with 646 UAVs reported downed or intercepted as part of the broader attack wave.
Kyiv and Russia's Volgograd region were hit overnight as both sides reported intercepting hundreds of drones.
Russia's Samara tank farm, part of the Transneft system and described as the largest in Europe, was reportedly targeted, while separate fires broke out near industrial sites in Volgograd.
Volgograd region governor Andrei Bocharov reported a "massive drone attack" on the region's industrial infrastructure; one person was injured.
Emergency services responded to a strike on a residential building in Volgograd, with two people reported injured.