Emmie, yes I do live in the capital.
Returning to the OP, I don't think that this incident should be called a demonstration or protest, it was apparently a bunch of thugs being disgusting. It's not uncommon for thugs to go around shouting and being disgusting- it's what they do. You shouldn't use such behaviour to try to prevent people from expressing their views in a peaceful way. Of course, peaceful demonstrations are often hijacked by thugs, but that's another matter.