I find myself sympathetic towards both sides - I can feel your pain being waken up at such an hour. On the other hand, I cannot fully support advocating against children playing, that just seems cruel in a way. You say you don't know which house it is exacly -I'd suggest reaching out to your closest neighbours, see if they feel the same, and if they know whose children they might be. Acting as a civil community will surely at least get you talking with the parents www.postcode-checker.co.uk