KANNAPOLIS (AP) — Four teenagers are recovering after being shot outside of where a graduation party in North Carolina.

WSOC reported the shooting broke out shortly after midnight Sunday in Kannapolis. Police say the four teenagers sustained non-life-threatening injuries.

Police said an argument broke out in the parking lot of Party Rentals Plus around 12:45 a.m., with eight shots reported fired. The shooter escaped and police are investigating to find out more about the shooter. Police say witnesses aren’t cooperating.

Police said people from multiple schools were invited to the private party. Officers had been at the party less than an hour before the shooting to turn down the music’s volume.