Police were told there was a man with a knife in the store on Stonegrove around 4.30pm yesterday (September 22). Paramedics arrived with officers and treated the teenager for a small cut on his knee. “A 15-year-old boy received treatment for a minor cut at the scene from the London Ambulance Service. “We sent an ambulance crew, paramedics in fast response cars and a member of our tactical response unit to the scene. “We treated a patient at the scene and took him to hospital.”