Police were called to a report of two men riding mountain bikes firing weapons in a Leeds street.
The incident happened on Compton Row in Harehills at 12.30am in the early hours of Tuesday (June 20).
It was not reported until several hours later, and police then went to the scene and recovered a number of blanks from the street.
Blanks are a type of non-lethal ammunition.
The scene was cordoned off until 7.50pm while West Yorkshire Police investigated.
Anyone with information is asked to call 101 quoting incident number 359.