Police were called to Harlesden after claims a gun was brandished when rivals clashed in the street following the Notting Hill Carnival.
Officers closed Harlesden High Street following reports of a firearm being seen during the street fight on Sunday at around 10.45pm.
A police helicopter patrolled the area searching for the alleged gunman but no one was arrested no a firearm recovered.
The road was reopened at 11.20pm with increased police patrols in the area.
Comments: Our rules
We want our comments to be a lively and valuable part of our community - a place where readers can debate and engage with the most important local issues. The ability to comment on our stories is a privilege, not a right, however, and that privilege may be withdrawn if it is abused or misused.
Please report any comments that break our rules.
Read the rules here