Nine gang members were killed and 18 more were injured in Waco, Texas on Sunday after a gun battle broke out between police and at least three rival motorcycle gangs, the Waco Tribune-Herald reports.

According to police spokesperson Sgt. W. Patrick Swanton, authorities were already at the scene when a gang fight broke out inside the Twin Peaks Restaurant at around 12:15 p.m. As the brawl spilled into the parking lot, the bikers reportedly escalated from “fists and feet to chains, clubs and knives, then to gunfire,” shooting at both rivals and police. From KWTX:

[T]he scene at Twin Peaks is “as secure as it can be right now,” Swanton said, but police are concerned that groups who were involved in the first incident may be moving to other locations in and around Waco where more violence could erupt.

Swanton said citizens should avoid the area until an all clear can be issued.

KXXV reports that restaurant management was aware that the gangs patronized their business and police had been warned of a possible confrontation ahead of time.

UPDATE 6:30 p.m.: KCEN News reports that 18 people were injured, primarily with bullet and knife wounds, and close to 100 weapons have been recovered from the scene.

“This could have been avoided if Twin Peaks management would have listened,” Sgt. Swanton told the station, saying the restaurant refused to cooperate with police. “Some people were just trying to enjoy a nice dinner. They didn’t deserve to see this.”

UPDATE 7:10 p.m.: According to KVUE Reporter Amber Downing, police say they don’t plan on releasing the names of the motorcycle clubs involved in the shootout, not wanting to give them the publicity.

All of those killed or injured in the fight are said to be gang members, although one officer was reportedly taken to the hospital for heat exhaustion.

[Image via KWTX]