The violence erupted shortly after noon at a busy Waco shopping center along Interstate 35 that draws a large lunchtime crowd. Waco police Sgt. W. Patrick Swanton said eight people died at the scene of the shooting at Twin Peaks restaurant and another person died at a hospital.
The nine killed were all members of biker gangs, he said, as were the 18 people who were taken to hospitals with injuries that include stab and gunshot wounds. Some victims are being treated for both, he said.
"This is probably one of the most gruesome crime scenes I've ever seen in my 34 years of law enforcement," Swanton said, later adding, "I was amazed that we didn't have innocent civilians killed or injured."
At least 100 people have been detained for questioning, Swanton said late Sunday night.
Swanton said at least five rival gangs gathered at Twin Peaks for a meeting that he said focused on turf and recruitment, two areas where the groups have often clashed. Preliminary findings indicate a dispute broke out in a bathroom, escalated to include knives and firearms and eventually spilled into the restaurant parking lot, he said. There were 150 to 200 gang members inside the restaurant at the time. Shots were fired inside and outside the restaurant, he said.
McLennan County Sheriff Parnell McNamara, whose office is involved in the investigation, said all nine who were killed were members of the Banditos or Cossacks gangs.
Swanton described the interior of the restaurant after a Sunday night walk-through, saying it was littered with bullet casings, knives, a club, bodies and pools of blood. Authorities would be working the rest of the night to process the reams of evidence, he said.
Police were aware of the meeting in advance, Swanton said, and at least 12 Waco officers in addition to state troopers were outside the restaurant, part of a national chain that features scantily clad waitresses, when the fight began.
"We've been made aware in the past few months of rival biker gangs ... being here and causing issues," Swanton said.
Officers shot armed bikers, Swanton said, adding that the actions of law enforcement prevented further deaths. It was not known if any of the nine dead were killed by police officers.
Swanton said that the restaurant's operators also were aware of the meeting in advance, and he described the management as uncooperative with authorities in addressing concerns.
"Apparently the management (of Twin Peaks) wanted them here and so we didn't have any say-so on whether they could be here or not," Swanton said.
A statement sent Sunday night on behalf of Jay Patel, operating partner for the Waco franchise, said, "Our management team has had ongoing and positive communications with the police," and added that the restaurant was cooperating with the investigation.
Swanton addressed Patel's statement late Sunday night, calling it a "fabrication."
Rick Van Warner, a spokesman for the Dallas-based corporate franchisor, said the company is reviewing the circumstances surrounding the shooting and is "seriously considering revoking" the Waco location's franchise agreement.
Van Warner said he couldn't address what the franchise owners "did or didn't do leading up to this," but added that the company is "very upset that clearly our standards of safety and security were not upheld in this particular case," he said.
Doug Greeness, a biker from Belton, Texas, was near the scene Sunday evening. He said he's a member of a family riding club and was waiting for friends to be released from custody so he could return home.
Greeness, who was not inside the restaurant when the melee broke out, described the event as a meeting of a biker association called the Texas Confederation of Clubs and Independents. He said the group meets to "discuss issues within the biker community."
Officers with numerous law enforcement agencies were seen parked along the service road for I-35 near the city and were stationed in several points in downtown Waco around the local convention center. Swanton said authorities are increasing security in the area to prevent further violence among the gangs.
In addition to local and state police, agents from the FBI and federal Bureau of Alcohol, Tobacco, Firearms and Explosives were also at the scene about an hour and a half south of Dallas.
Associated Press videographer John L. Mone in Waco contributed to this report.