Shots were fired during a disturbance which police described as "serious" and "reckless".
Officers have appealed for information following the incident in Heather Park Drive, at the junction with Lyon Park Avenue, in Wembley, on January 11 at around 5am.
No one was injured during the disturbance.
Trident Gang Crime Command are investigating and have asked anyone who may have seen anything suspicious, or who has any information concerning the incident, to come forward.
Detective Inspector Glenn Butler said: "This was a very serious incident and I am determined that the perpetrators face the consequences of their actions.
"Innocent bystanders could have been seriously injured by such reckless behaviour and I would urge anyone with any information to come forward."
Anyone with information should call Trident on 0208 358 0578 or Crimestoppers on 0800 555 111.
There have been no arrests and enquiries continue.