Police were called at 4.31pm on 23 June to a report of a stabbing around Dobson Close, NW6.
Officers attended along with colleagues from the London Ambulance Service and the Air Ambulance Service and treated a 15-year-old boy with a stomach wound.
The exact circumstances are still under investigation
The injuries are not life-threatening or life-changing. He was taken to a local hospital.
Anyone with information should call 101 with CAD reference 5349//23Jun.
Alternatively contact Crimestoppers 100 per cent anonymously on 0800 555 111 or online at crimestoppers-