TEMPE, Ariz. -- Tempe Police say 13 people were wounded following a shooting outside a night club.
Sgt. Steve Carbajal said at least two of the injured are in serious condition, while the others were treated at hospitals for more minor wounds. Initial reports said seven were shot, but as more victims drove themselves to the hospital the number grew.
Police are not sure what prompted the shooting, but they are searching for two young black men seen fleeing the club on foot.
The shots were fired outside the Clubhouse Music Venue on Broadway Road, which is a few blocks southeast of the Arizona State University Tempe campus.
Sgt. Carbajal said the shooting came during "some sort of altercation" at the club, where a rap music concert was going on. Rapper Nipsey Hussle was set to perform.
Witnesses describe the scene as "chaotic."
"People stampeded over security. Not what I expected to be doing on a Friday night -- dodging bullets," said Paul Butler, who witnessed the shooting.
Butler and other witnesses say a large crowd was waiting outside the club for the doors to open when gunfire broke out.
Neither witnesses nor police are sure of a motive.