Police in Waco, Tex., said Monday they had arrested 170 people after a shootout involving multiple biker gangs at a restaurant that left at least nine people dead.

While investigators worked to piece together precisely what happened on Sunday, authorities said they remained alert after receiving threats of possible retaliation against police officers after the chaotic brawl.

The sea of people arrested were charged with engaging in organized criminal activity, which is a capital murder charge due to the number of victims, Sgt. W. Patrick Swanton, a Waco police spokesman, said at a news conference Monday.

“There was a significant danger here yesterday because of the amount of violence that occurred behind us here,” Swanton said while standing in front of the restaurant.

The spasm of deadly violence began when members of biker gangs began fighting inside the restroom of Twin Peaks, a restaurant in a retail strip on Interstate 35 known to locals as a biker bar. In addition to firearms, the fighting involved fists, feet, knives and chains, officials said.

Swanton said that gunfire began inside the restaurant before spilled out onto the patio bar area and then into the parking lot. Several shooting victims were found near the front of the restaurant or in the parking lot around it, he said.

“We had wounded inside, we had people stabbed, we had people shot and we had people beat,” Swanton said.

There were already 18 police officers and another four officers from the state Department of Public Safety in the parking lot because officials had received information about the danger posed by these gangs being in the same place, Swanton said. Once outside, the bikers turned their gunfire on the police officers who responded, he said.

“Those officers’ reactions…to a very hostile, deadly situation saved our citizens’ lives yesterday afternoon,” Swanton said.

After the fighting, authorities said that nine people had been killed, and remarkably no police officers or other bystanders in the area had been injured.

The 170 people taken into custody were initially taken to the city’s convention center for processing before being brought to the McLennan County Jail, which was still working to process all of these individuals on Monday.

Police originally said 192 people were arrested, but Swanton revised that number on Monday and said it was possible the number could still change as they continued to sift through all of the names.

The jail, located about 15 minutes away from the retail strip where the shootings occurred, was still working Monday morning to process all of the people who had been arrested, an official said.

Authorities continued to investigate the area around the Twin Peaks restaurant on Monday. More than 100 motorcycles and dozens of other vehicles remained in the parking lot.

“We’re not in a rush,” Swanton said. “This is obviously a very large investigation involving numerous agencies and organizations, and we’re going to get it right.”

[Police: Restaurant has some answering to do]

Swanton said police have received information about “payback” against officers and reports of bikers flooding into the area after the shooting. As a result, he said officers have been stationed around the region to watch for any threat.

“There was a green light put out on law enforcement is our understanding from last night,” he said Monday. “We’re aware of that threat, and we have the appropriate response if we have to face that.”

The brawl occurred on Sunday at noon at the sports bar, with violence erupting and sending terrified patrons diving for cover in a busy Central Texas shopping center.

Swanton was critical of the restaurant, saying after the shootout that its management has “not been of much assistance to us.”

It was typical to see motorcycles parked outside of Twin Peaks, said Saul Cornejo Bravo, 19, a server at a Mexican restaurant next door.

“But not that many, especially on a Sunday afternoon,” he said. “Usually I see them there later at night.”

Bravo said that he was working on Sunday when the shooting occurred, and within seconds he saw emergency vehicles flooding the parking lot.

He saw one man wearing a biker’s vest who appeared to have been shot in the stomach. Paramedics tried to perform CPR for several minutes, Bravo said. “Then they just covered him up,” he said.

Off-duty police officers shopping in the retail strip rushed to the scene despite lacking any protective gear, Swanton said. Meanwhile, some of the people who ran away from Twin Peaks as the chaos unfolded took shelter behind an empty building.

“We sat there gathering our wits,” said J.R., who works at Cabela’s Outpost, an outdoors store across the parking lot from Twin Peaks. “At first you think it’s like a carjacking or something. But then, with all the shots and people running you realize it’s something more serious.”

Police said in a statement Monday said the Twin Peaks restaurant and parking lot were “still a very active crime scene” — one that “is littered with bullets, blood and other evidence. Civilian as well as Police units with bullet holes remain to be processed.” Parts of Central Texas Market Place, where the Twin Peaks sports bar is located, were expected to remain closed for the day, police said.

Five known gangs were believed to be involved in the brawl, Swanton said, but he would not identify them on Monday.

“I am not about to give them the respect of mentioning their names…. We don’t care what their names are, and we’re not going to give them publicity,” he said.

Swanton said it was still not clear how many shots were fired by gang members or police. It was unclear whether any of the nine bikers killed in the fight were shot by police.

“It was chaos,” said J.R., who declined to give his last name. “People were screaming and going crazy. Most of it seemed to be in the parking lot, and it was over very quickly.”

All of the people charged with organized crime activity will face a capital murder charge, Swanton said, due to the number of people killed Sunday. Texas state law says that a person who murders more than one other person “during the same criminal transaction” can face this charge, while  suspects can be charged with organized criminal activity if they carry out a murder or capital murder as part of a criminal street gang.

Eighteen people were taken to hospitals after the brawl with injuries that included stab and gunshot wounds, Swanton said. Some victims were being treated for both, he told reporters in Central Texas on Sunday.

“I was amazed that we didn’t have innocent civilians killed or injured,” Swanton said, according to the Associated Press, which noted:

Many streets were nearly deserted in Waco, apart from law enforcement officials keeping watch, as night fell following a shootout between rival motorcycle gangs at a restaurant that left nine bikers dead and raised the specter of further violence.

Authorities increased security to quell other possible attempts at criminal activity in the Central Texas town following the melee Sunday.

McLennan County Sheriff Parnell McNamara said all nine who were killed were members of the Bandidos or Cossacks gangs, according to the AP.

A threat assessment released last year by the Texas Department of Public Safety classified the Bandidos gang in the second-highest tier threat. The Department of Justice lists the Bandidos as one of the handful of organized motorcycle gangs that “pose a serious national domestic threat.”

[How the Bandidos became one of the world’s most feared biker gangs]

For some in the region, they could sense rising friction between the different motorcycle gangs when members were at the same bars and restaurants.

“There were these little tiffs going on, and then you add alcohol,” said Richard, a motorcycle enthusiast who also declined to give his last name. “I just felt like there was tension.”

He said biker had activity had increased in and around Waco in the last few years, probably because of its proximity to both the Dallas-Fort Worth area and Austin.

“Ninety nine percent of of the people who ride bikes are good people, doctors, lawyer, engineers,” said Richard, an engineer. “It’s the one percent that don’t care about anything. They say, ‘We’ll do what we do.’ It was a rude awakening for the rest of us. Is this going to land on our doorsteps? Is this what we have to look forward to? What happens if we’re wearing the wrong shirt in the wrong neighborhood? That’s what has a lot of us worried.”

On Sunday, witnesses described seeing a mass shootout that involved dozens of of guns being fired inside the restaurant and in the parking lot along Interstate 35, according to CBS affiliate KWTX. The station reported that panicked patrons and employees sought refuge from the mayhem in the restaurant freezer.

Hours later, authorities from multiple law enforcement agencies — including local and state police, and the federal Bureau of Alcohol, Tobacco, Firearms and Explosives — were still trying to secure the area and survey the large crime scene, which was littered with more than 100 weapons.

“In 34 years of law enforcement, this is the most violent crime scene I have ever been involved in,” Swanton said, according to the Waco Tribune-Herald. “There is blood everywhere. We will probably approach the number of 100 weapons.”

Swanton called it “one of the worst gun fights we’ve ever had in the city limits. They started shooting at our officers.”

The officers returned fire, Swanton said, and some armed bikers were shot by police. Swanton defended the officers’ actions and said they prevented more deaths.

“Their action has saved lives in keeping this from spilling into a very busy Sunday morning,” he said, according to CNN. “Thank goodness the officers were here, and took the action that they needed to take to save numerous lives.”

Authorities said it was not immediately clear what precisely triggered the violence, but the potential for conflict did not surprise the Twin Peaks staff or officers. McLennan County District Attorney Abel Reyna told the AP that tensions between the gangs had been building for months.

Police were bracing for violence: Swanton said Waco police officers and state officers were at the sports bar when the fighting began and that they had secured the area because they “expected issues.” He said the restaurant’s management requested the officers in anticipation of trouble.

“We have been made aware in the last few months of rival biker gangs — rival criminal biker gangs — being here and causing issues,” Swanton said. “We have attempted to work with the local management of Twin Peaks to get that cut back, to no avail. They have not been of much assistance to us.”

Jay Patel, operating partner for the Twin Peaks franchise in Waco, said in a statement Sunday: “We are horrified by the criminal, violent acts that occurred outside of our Waco restaurant today. We share in the community’s trauma. Our priority is to provide a safe and enjoyable environment for our customers and employees, and we consider the police our partners in doing so.”

Patel added that “our management team has had ongoing and positive communications with the police and … we will continue to cooperate with the police as they investigate this terrible crime.”

Swanton called Patel’s statement a “fabrication,” according to the AP, which reported that the Waco police “described the management as uncooperative with authorities in addressing concerns about the gangs.”

“Are we frustrated? Sure,” Swanton said, according to CNN. “Because we feel like there may have been more that could have been done by a business to prevent this.”

Police said Monday that the Texas Alcoholic Beverage Commission “is implementing a Summary Suspension closing Twin Peaks for at least 7 days. This is not a punitive action on TABC’s part but done due to the ongoing danger it presents to our community.”

CBS affiliate KWTX reported that the Twin Peaks corporate office canceled the Waco store’s franchise agreement on Monday.

“We are in the people business and the safety of the employees and guests in our restaurants is priority one,” the company said in a statement, according to KWTX. “Unfortunately the management team of the franchised restaurant in Waco chose to ignore the warnings and advice from both the police and our company, and did not uphold the high security standards we have in place to ensure everyone is safe at our restaurants.

“We will not tolerate the actions of this relatively new franchisee and are revoking their franchise agreement immediately. Our sympathies continue to be with the families of those who died and are very thankful no employees, guests, police officers or bystanders were hurt or injured.”

A witness who had just finished lunch at a nearby restaurant told KWTX that he and his family walked into the parking lot when they heard multiple gunshots and saw wounded people being removed from the scene.

“We crouched down in front of our pickup truck because that was the only cover we had,” said the man, who asked not to be identified.

Another witness, Michelle Logan, told the Tribune-Herald: “There were maybe 30 guns being fired in the parking lot, maybe 100 rounds. They just opened fire. … There’s a lot of people in the hospital, a lot of people shot.”

Vehicles parked near the restaurant were riddled with bullet holes, the newspaper noted.

Headquartered in Dallas, Twin Peaks is a casual dining chain with dozens of locations nationwide that employs a largely female staff scantily clad in plaid shirts and mini shorts.

“Twin Peaks Girls,” the company advertises, offer customers “signature ‘Girl Next Door’ charisma and playful personalities.”

The Waco location opened in August and was touted by a company spokesman as offering 24 types of beer and 55 flatscreen TVs, as well as “Bike Night” on Thursdays.

“Get revved up and ready to go at Twin Peaks bike night,” a calendar on the Twin Peaks Waco Web site advertised.

Holley, du Lac and Berman reported from Washington. Madigan reported from Waco. 

[This post, originally published on May 17, has been updated multiple times.]