I think it's worth linking to an item from the Kennington Association who have been contacted by the Vassall Safer Neighbourhood team, to warn people of a scam being attempted around the Oval area.
If youths come knocking at your door, requesting money to support a sports club, ask them for ID and do not give them any money. If you can contact the local police, they will come and check to see whether the group is authorised (it looks unlikely).
See the Kennington News blog for further info.
Hoax caller rang police to report stabbing outside Kennington Tube station | London Evening Standard - Hoax caller rang police to report stabbing outside Kennington Tube station | London Evening Standard
12 hours ago