Recently I encountered two young boys on the bus who were shouting and swearing at random passengers constantly - literally turning and screaming at them "hey, F YOU, you are shit, the F you are looking at" and so on, you get the picture. And when a passenger asked them to stop, behave, the response would be among the lines "Want me to beat ya?", "Do you know who my parents are you shit", again you get the gist. They looked about 11.
Besides that, they were kicking the bus and each other, quite strongly. Strongly enough that at one point driver stopped the bus and came upstairs, physically put them apart to separate chairs and told them to cut it off. One of the boys responded "You cannot touch me", to which bus driver responded, "Then keep it up and I will call the police, they can touch you.".
This didn't help either, they swore more and more at every passenger on the bus, making few people head to debus on the next stop after being targetted, and at least a few I am more than sure that this was not their stop. So it kept going on, for good 30 minutes now.
So I wonder what can I do in this situation as one of the passengers? The bus driver clearly didn't want to take it further, but I also don't particularly enjoy having to cope with this, and if they were adults, I would likely already call the police myself. I honestly considered doing it and reporting two lost kids on the bus, but eventually decided against it for some reasons.
I imagine that their age will play a role, and while my estimate at 11 may not be perfect, if a year or two up, or down, changes things I am wondering how.
Update: I did record their behavior and filled a crime report afterward. I am mostly interested is there anything I can do while still on the bus. I personally do not feel threatened by two 11-year-old boys, nor pay much attention to the curses, but also I saw that it was making people really uncomfortable and pushing them off the bus. And that just does not sit well with me.