The bigger bird is a black kite, two others, attacking, are Falcons. What kind of Falcons are they? I know that in a couple of kilometers from the place I've seen them, there is a peregrine falcon's nest. But perhaps these two are Eurasian hobbies because they sounded pretty much like hobbies. I just can't estimate their size relatively to that of the kite. Sorry for the quality of the photos, they are screenshots of my video made on my phone.