Yes there are some racism elemants to it from both sides or culture clashes if you want to call it and some intolerance to others
BUT
in the most part it is a mob of largley young males who are going around in large groups because they are to gutless not to, acting in anti social violent manner with very little respect for the law or anyone else.
and this description is not restricted to any particlar group.
Adopt a zero tolerance law and order policy against them and continue to until they decide to behave.