British Transport Police officers in the area altered MPS officers shortly before 02:25hrs on Thursday, 11 November to a stabbing on Cricklewood Broadway, NW2.
Medics from the London Ambulance Service also attended and found two 19-year-old men who had been stabbed.
One man was treated at the scene for an injury to his hand. The other man was taken to hospital and his condition has been assessed as non life-threatening.
A crime scene is in place along with a number of road closures as officers investigate.
Anyone who witnessed the incident or who has other information and has not yet spoken to police should call 101 and quote reference 577/11NOV.
Information can also be provided to Crimestoppers, anonymously, on 0800 555 111.
