11:45 AM PT -- Sources close to Nipsey tell TMZ he wasn't present for the shooting. We're told he was performing across town at the Shrine Auditorium for YG's concert, and planned to arrive to his own event afterward. Obviously, that got scratched.

Shots were fired at a Nipsey Hussle album release party Saturday night in L.A., and someone got hit.

Someone started shooting in the parking lot outside World on Wheels, a roller skating rink in Venice. One person was shot in the thigh.

Cops swarmed the area on the ground and in the air. The shooter got away and police were left high and dry after the victim refused to cooperate.

The shooting went down at around 11:30 PM. We're told people inside the roller rink freaked out ... many fearing it was a repeat of what happened Friday in Florida.

Police didn't see Nipsey after the shooting. It's unclear if he had already left.