Some of the victims may also have been trampled when gunfire rang out inside the Power Ultra Lounge in downtown Little Rock around 2:30 am, local KATV reported.
"We do NOT believe this incident was an active shooter or terror related incident," the Little Rock police department wrote on Twitter.
"It appears to have been a dispute at a concert."
Police later tweeted that "ALL 17 confirmed shooting victims are alive," and that one of the shooting victims "that was critical has been upgraded to STABLE."
According to the nightclub website, an artist by the name of Finese 2 Tymes had been scheduled to perform.