There are several questions I have.
First - if they are flares, they are maintaining altitude well beyond what I would expect.
Second - the object which strikes them seems to pass through them without causing much change in their position.
Third - what did they shoot it with? Most (air to air) missiles detonate a shrapnel warhead prior to striking the target. Skin strikes aren't unheard of, but rare outside of missiles designed specifically for kinetic kills.
If those are flares, they have some means of behaving as though neutrally buoyant and they are able to be "shot through" without losing their properties.
Those would not be any standard target flare I am familiar with. Certainly not completely impossible to see being designed somewhere by human hands - but this begs the question of who they are and why they are trolling our military with them.