A mixtape party at SOB's for a rapper Fat Trel turned violent just after midnight today. Four people were shot and injured at the Manhattan nightclub around 12:15 a.m.—and it was apparently after "a gang member from New Jersey insulted New York City."

The Post says three people—two men and a woman—were shot in the leg while one person was grazed by a bullet. The Daily News says two had leg wounds, while two others were grazed. A DJ at the club told the News, "I’ve never been so scared because I didn’t know where the shots were coming from. Everybody is jumping on each other, trying to get away from the action."

Another clubgoer said to the Post, "It was mayhem. We heard four or five shots. People were ducking and rolling on the floor," then people fled for the doors. The Post has details behind the beef:

The argument allegedly started when a Bloods gang member from New Jersey approached the stage and started to trash talk New York City, witnesses said.

“It was stupidity between some Bloods and Crips,” a witness said. “It was so ignorant. People started yelling at each other and then a gun got pulled.”

The shooting occurred before Fat Trel even performed anything from his mixtape, "Sex, Drugs, Money, & Guns."

The investigation is ongoing.