HOLLYWOOD (CBSLA.com) — A mob estimated at 40 people reportedly went on a robbery spree Tuesday night in Hollywood, Los Angeles police said.

The LAPD’s Hollywood Division said they were flooded with 911 calls around 9 p.m. about a mob in the area of Hollywood Boulevard and Cahuenga and later near the intersection of Western Avenue and Santa Monica Boulevard.

A dozen people, including 11 juveniles, were arrested for looting, assault, robbery and other charges.

“Groups that ranged anywhere from 15 of these kids to as large as 40 . . . either knocking people down and taking their cell phones, running into a business and taking merchandise, taking their cash register or causing havoc like breaking windows,” Cmdr. Dennis Kato said.

It was unclear what prompted the spree, but police believe it was not a protest in response to the George Zimmerman verdict.

“The individuals out there were not engaged in any kind of protesting, at least not peaceful protesting,” Lt. Ray Valois told KNX1070.

12 In Custody After Mob Goes On Robbery Spree In Hollywood

“Hollywood units responded very very quickly, and within minutes we had almost all of the suspects in custody,” he said. “In the next few days, we are going to have an extremely large presence along the boulevard to prevent this type of incident from occurring here in the future.”

Officials were trying to determine if the incident was related to wilding, a popular east coast trend that involves masses joining together to commit crimes.

“Mass groups of kids would run into a store where they know that one security guard can’t stop them and will just take merchandise and run out,” Cmdr. Kato said.

No serious injuries were reported.