MADISON, Wis. -

Shots might have been fired during a disturbance involving 15 to 30 people on Madison’s north side Friday night, according to a police report.

Officers were called to the 3700 block of West Karstens Drive at 9:49 p.m. for a report of a disturbance. Police said a crowd dispersed as officers arrived on scene.

A witness told police someone fired a gun into the air during the street dispute. Police said no shell casings were found but parts of a BB gun were found.

Police said the disturbance began as a house party.