A multiple shooting inside a packed Minneapolis nightclub over the weekend has left police with a sprawling investigation — a city report lists 52 witnesses to the crime — that produced no arrests and little clarity Sunday.

Nine people were shot inside the 400 Soundbar, 400 3rd Av. N., including a Minnesota Vikings defensive lineman, but only two of the victims were seriously wounded and both are expected to survive, according to authorities.

Authorities were tight-lipped about the investigation Sunday; none of the victims have been publicly identified, other than the Vikings player Linval Joseph.

Joseph, who is expected to play in the Vikings’ Sept. 7 season opener, said he was at the club when someone inside the bar started shooting at 1:40 a.m. Saturday. In a statement Sunday morning, Joseph said he was “extremely thankful” to have escaped without serious injury and reiterated that he was “an innocent bystander,” an account the team endorsed.

Assistant Minneapolis Police Chief Matt Clark said the shooter had an intended target and that the incident was gang related.

With so many witnesses and victims, investigators face a lengthy effort to assemble a coherent picture of what happened in the club. No description of the shooter was provided Sunday, but authorities said that was to protect the integrity of the investigation as they collect witness statements. No video of the shooting was released for the same reason, nor did police want to give any description of a gun found at the scene, Clark said.

Minneapolis City Council Member Jacob Frey said he had met with the nightclub’s owner, Johann Sfaellos, in July to talk about security at the club. Frey said it was the third such meeting with the nightclub to resolve city concerns. The details of those meetings were not available over the weekend, but a city spokesman on Sunday said more information about city efforts to regulate the club would be available Monday.

The city quickly revoked the 400 Soundbar’s license Saturday and ordered it closed. Sfaellos said he agreed to shutter the club and told the Star Tribune on Saturday that he doesn’t know how the shooter was able to get a weapon past the club’s security measures.

The attack was the latest in a string of shootings downtown that police have linked to gangs. A man was shot dead inside Epic nightclub last November in a gang dispute. Two drive-by attacks in April that wounded three people downtown also were linked to gangs.

Another Minneapolis club owner said there’s “no easy answer” to such crime problems, but that clubs employ a variety of measures to provide security for their patrons.

“I don’t want to be cheeky but I’m sure they posted a banned weapons sign at their entryway,” said Brian Michael, owner of Auggie’s Cabaret in downtown Minneapolis. “The criminals in society, they don’t care about the rules.”