Undocumented footage coming from the battlefields in Ukraine today, shows a large-scale attack of MLRS Rockets, presumably being fired at Russian occupied positions.

Although we cannot visually identify the munitions being fired, the sound and firing sequence timing fits the description better than a BM-21 GRAD. This is obviously speculation at this point, but hey... I'm not rocket expert.

Let me know in the comments below what kind of rocket system you think this is.