An altercation at a grocery shop near Willesden Green station led to partial road closures as emergency services responded.
A person received a cut during the commotion in a shop in Walm Lane, close to the station and was treated on the scene by paramedics.
Metropolitan Police and London Ambulance service were called to the scene, to reports of a case of actual bodily harm, although no arrests have been made in connection with the incident.
The incident occurred during rush hour, at 6.25pm, on Walm Lane, which has a shopping arcade, several bus routes and the Willesden Green Tube station.
Photos from the scene show temporary cordons on the road, while paramedics give treatment at a bus stop outside the station.
A spokesman for Metropolitan Police said: "We were called to an altercation at a shop in Walm Lane at 6.25pm. Nobody was seriously injured in the incident.
"Police are investigating an allegation of assault, although no arrests have been made yet."