What the Hell Is Happening Here?

I read the photo caption but I still don't know what's going on here: Two Japan Ground Self-Defence Force's AH-64DJ Apache attack helicopters flying over eight of tanks shooting pyrotechnics in a live-fire exercise near Mount Fuji.

What are the pyrotechnics for? Why are they being fired that way? Is this an exercise to distract Godzilla with pretty sparks?

If you are in the military, please explain in the comments. [Flight Global]