A shootout among rival motorcycle gangs at a restaurant in Waco, Texas, left nine bikers dead and 18 injured, and sent patrons and bystanders fleeing for safety, a police spokesman said on Sunday.

The violence erupted shortly after noon at the Twin Peaks restaurant on Interstate 35. Waco police Sergeant W. Patrick Swanton said eight people died at the scene of the shooting and another person died at a hospital.

The nine killed were all members of biker gangs, as were the 18 people who were taken to hospitals with injuries that included stab and gunshot wounds.

"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."

Police said that they were amazed that no one eating lunch in nearby restaurants was wounded in the crossfire as members of up to five gangs fought in a parking lot with guns, clubs, knives and chains.

Police said 192 people were being arrested on Monday in connection with the shootout.

Those under arrest will face charges of engaging in organized crime, police said in a statement.

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.

McLennan County Sheriff Parnell McNamara, whose office is involved in the investigation, said all nine who were killed were members of the Bandidos or Cossacks gangs.

Swanton said the interior of the restaurant was littered with bullet casings, knives, a club, bodies and pools of blood.

Police were aware of the meeting in advance, he said, and at least 12 Waco officers in addition to state troopers were outside the restaurant 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 were also aware of the meeting in advance, and he described the management as uncooperative with authorities in addressing concerns.

AP - AFP