An FSB base.

I cropped and stabilized the video which makes it harder to tell that the camera is moving, not the smoke of the first explosion. Here’s the original video.

https://files.catbox.moe/oa3pmu.mp4

I realize what you were asking about now. The first thing that’s visible is just black smoke from the explosion of the STING interceptor drone.

It’s a Geran-2 attack UAV, which is a copy of the Iranian Shahed UAV.