Two people were killed and four others injured in a gunfight between rival motorcycle gangs in Augusta, Ga., over the weekend.

In the aftermath, police found 150 shell casings at and near the scene, a motorcycle clubhouse in a residential area. Some of them were strewn as far as a block away from the carnage.

Twelve people, including some of those injured, were charged with murder and aggravated assault, Sheriff Richard Roundtree said. More charges were pending on Monday.

A prior confrontation in Florida between the two arch-enemy clubs, the Thugs and the Outkasts, was the likely starting point for the confrontation, Roundtree said. He did not provide details.

“With the amount of firepower and carnage we saw at the scene, this could have been a much more horrific event,” Roundtree said during a Monday news conference.

The initial call came in at 6:53 p.m. on Saturday, when the Richmond County Sheriff’s Office responded to a report of “shots fired with several people down,” police said in a statement. Arriving officers found two men shot at least once who “succumbed to their injuries on scene.”

The Richmond County Coroner’s Office pronounced Germane Farrell, 51, of Daytona Beach, Fla., and Keith Coates, 30, of Valdosta, Ga., dead about an hour later. Three of the four injured were still hospitalized on Monday, Roundtree said, providing no information on their conditions.

Members of both clubs were among the injured and arrested, and 11 of the 12 charged were from out of town, Roundtree said.

“This was a coordinated attack by individuals who came from as far away as Florida,” Roundtree said. “We’re talking about traveling three or four hours to come to Augusta, armed to engage in gun violence.”

Multiple guns were found inside the clubhouse, according to Roundtree, who noted that most of those involved in the fight were not cooperating with investigators.

With News Wire Services