I read this as "stop using your constitutional right to protest or we will attack you". These curfews are clearly being used to suppress protests, and I think disobedience is crucial here and does not justify police brutality in any way against otherwise peaceful protesters. Again as others have pointed out, a small group of violent protestors does not give police the right to attack clearly nonviolent protestors either.
I think if we banned police from getting near these protests at all / only getting involved with people causing physical violence, it would be a great step to actually minimizing the exact things the curfews are intended to address.