There's nothing I can do is there, despite wanting to?

[KerfuffleShuffle]

Outside our flat is a park and playground. Earlier this evening there were 3 adults - 2 male and 1 female - and 2 young children in the playground. Both males had cans of beer in their hands and all 5 definitely knew or were related to each other. I heard one of the males screaming to one of the kids (and I heard it clear as day around 100m away) get down you f*King skank. A few minutes later I heard lots of swear shouting and saw one male hit a child so hard that the child went over the rails of the climbing frame onto the floor below (about 1m down). The child was crying but got up and attempted to fight this man. The man then turned this into a very rough 'game' of chasing where the child fell a few times more. I know IANBU to call this downright unacceptable and physical abuse but there's not actually anything I can do about this is there? I don't know their names or where they live in this densely populated estate.

Call the police and give descriptions?

Did you call the police? I would have at the time. It might be worth falling 101 now in case there is CCTV.

Sorry you had to witness something so awful

Call the police. They may have a file as long as your arm or there may be CCTV in the area.

I know I could have rang the police but whilst the 101 call centre would be understanding there's really not much that could be done on generic descriptions alone. The policing team are great round here but there's really not enough resources for them. It's a high crime, deprived inner city area and last January when there was an elderly man stood fully naked in the park in the middle of the night with clearly some mental health crisis going on it took the police over an hour to arrive due to lack of availibility. I can only hope this family will come/are under schools and SS radar.

I'd have thought 999 was more appropriate - child being abused.