If the witnesses did in fact see this happening, I hope they called 000 right away....the next day is not good enough.
And if you ever ring the police when there is trouble brewing while at camp, and they seem to not have any interest in coming out, mention that you believe there are firearms being discharged....that will usually get them moving.....obviously loud music isn't a police matter !!
Another trick ( especially during the day ) is to get your camera and pretend to take pics of people running amuck ( or actually take the pics )