Chattanooga, Tenn., Capturing: Three useless, 14 injured in capturing the place a number of victims had been hit by fleeing vehicles

Police responded to reports of a nightclub shooting just before 2:45 a.m., Jeremy Eames, a spokesman for the Chattanooga Police Department, told CNN. Officers found several victims upon arrival and began providing medical assistance.

A total of 14 victims were shot, while three others were hit by vehicles trying to flee the scene, Eames said. Among the three deaths, two were from gunshot wounds and one from injuries sustained after the victim was hit by a vehicle, he said.

Police believe several shooters with different types of firearms were involved. There are no suspects in custody and police have yet to identify potential suspects or victims.

A motive for the shooting is unclear, but authorities believe the shooting was an isolated incident “in which one or more of the victims were targeted.”

The shooting comes as the nation jitters after consecutive high-profile shootings, including that at a convenience store in Buffalo, New York; at an elementary school in Uvalde, Texas; and a hospital in Tulsa, Oklahoma. It is also the second major shooting in Chattanooga in as many weekends. Six people were shot dead in the city center last Saturday night after an altercation between two groups, police said at the time. No casualties died, although two were seriously injured.

In a news conference on Sunday, Mayor Tim Kelly expressed his frustration, telling reporters, “I’m tired of standing in front of you and talking about guns and dead bodies.”

According to the Gun Violence Archive, there have been 12 mass shootings in the country since Friday, including in Philadelphia, where police say at least three people were killed and 11 others injured when multiple gunmen opened fire Saturday night.

“The rise in gun violence that we have seen across the country and here in Philadelphia not only makes me heartbroken but also angry,” Philadelphia Mayor Jim Kenney said Sunday.

“Once again we see lives senselessly lost and injured in yet another horrific, brazen and despicable act of gun violence.”

Chattanooga’s mayor vowed he and the city council would take time to address gun violence in the coming weeks, saying they would “treat this like the crisis it is.”

The mayor himself is a gun owner and a lifelong hunter and shooter, he said, and he supports responsible gun ownership.

“But Congress has to do its job and pass sensible regulations that will help stop this nonsense,” he said.

“That doesn’t mean taking guns away from responsible gun owners, but it does mean mandatory background checks and bans on high-capacity magazines that allow shooters to injure dozens of people without even having to reload.”

CNN’s Dakin Andone and Hannah Sarisohn contributed to this report.