Update as of 7:30 a.m. EDT: Police in Waco, Texas, have arrested and booked 192 people over a shootout among rival gang members that killed nine people and injured 18 others, the Waco police department wrote on its Facebook page early Monday. 

“They will all face Engaging in Organized Crime charges,” the department said, in the statement, adding that the Twin Peaks restaurant, where the shooting took place Sunday, will be closed for at least seven days.

Update as of 6:00 a.m. EDT: Police in Waco, Texas, received threats from biker gangs after a shootout among members of different gangs killed nine people and injured 18 others outside a sports bar Sunday, CBS 11 News wrote on its Twitter account.

Over 150 people are still detained by police as an investigation into the deadly shooting is reportedly underway, the network added.

Original story:

A possible dispute over a parking space may have sparked a clash among rival biker gangs that left nine people dead and 18 injured in Waco, Texas, police said. As many as five biker gangs were believed involved in the melee outside the Twin Peaks Sports Bar and Grill.

“These are very dangerous, hostile biker gangs,” Waco Police Sgt. Patrick Swanton told reporters. “A lot of innocent people could have been injured today.” Swanton said police were on the scene before the fracas began, likely preventing more carnage, Reuters reported. He described the scene as "the most violent crime scene I have ever been involved in."

Eight of those killed died at the scene and one died at an area hospital, all of them bikers, Swanton said.

The Waco Tribune reported more than 50 weapons -- clubs, knives and firearms -- were found at the scene in the parking lot of the Central Texas Marketplace shopping mall. Senior Department of Public Safety Trooper D.L. Wilson said more than 100 people were questioned.

Several streets, including bridges over the Brazos River, were closed off to keep more gang members from coming into the area. Other restaurants and bars were reported closing early, fearing potential violence.

Swanton said the altercation started in a restroom around noon, local time, before spilling into the bar and then the parking lot.

The Tribune said two of the gangs involved were identified as the Bandidos and the Cossacks. Investigators said at least two of the gangs were trying to do some recruiting.

“This is one of the worst gun fights we’ve ever had in the city limits. They started shooting at our officers,” Swanton said. “There is blood everywhere."

“We crouched down in front of our pick-up truck because that was the only cover we had,” said one man who had just finished eating lunch with his family when the gunfire broke out,  KWTX-TV, Waco, reported.

McLennan County District Attorney Abel Reyna had told reporters the restaurant has been a concern, especially on Thursdays, the restaurant's weekly "Biker Night."

The restaurant chain, which features scantily clad servers, issued a statement on its Facebook page expressing horror at "the criminal, violent acts that occurred outside of our Waco restaurant today."