CCTV footage on Thursday showed the roof of a building east of Engels airbase getting blown off due to the impact of a nearby blast.
Video on Russian Telegram channels showed a major blast spreading out from the airfield, wrecking nearby cottages. Video published on social media and filmed from Engels shows a mushroom cloud rising on the horizon at the time of the blast. Russia's defence ministry said air defences had shot down 132 Ukrainian drones over Russian regions.
The video was verified by Reuters based on the position and shape of buildings and showed a plume of smoke rising above damaged cottages. The location of the video was verified from the position and shape of buildings and trees which matched satellite imagery. The smoke cloud also came from the direction of the air base.
The base in Engels, which dates back to early Soviet times, hosts Russia's Tupolev Tu-160 nuclear-capable heavy strategic bombers, known unofficially as White Swans.
Roman Busargin, the governor of Saratov, said there had been a Ukrainian drone attack on the city of Engels that had left an airfield on fire, and that nearby residents had been evacuated. He did not specifically mention the Engels base, but it is the main airfield in the area.