Zimmerman Verdict: Los Angeles TV News Crew Attacked Amid Protests (Report)

During an 11 p.m. news conference, Mayor Eric Garcetti says 13 people have been arrested.

A KCBS/KCAL crew was attacked as riots broke out around the city in protest of the George Zimmerman acquittal, according to various reports.

As the Los Angeles Police Department sought to get the situation under control, the news crew was attacked at near the corner of 43rd Street and Crenshaw Boulevard. Further details were not immediately available.

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The LAPD had already issued a citywide tactical alert Monday night, on the third day of protests following a Florida jury's not-guilty verdict in the Zimmerman case. He had been on trial for killing 17-year-old Trayvon Martin.

Around 10 p.m., the LAPD announced it had declared an unlawful assembly, with protesters given a certain amount of time to disperse or be arrested.

According to the L.A. Times' Ruben Vives, the LAPD had engaged in a standoff outside a Walmart in the Crenshaw area. Some shoppers said demonstrators had tried to break open the jewelry displays inside the store.

Meanwhile, KCBS/KCAL reported that demonstrators were running, biking or skateboarding in the middle of the street at one point. Some climbed on top of vehicles, kicked in windows and knocked over trash cans.

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Vives reported that as police tired to get the situation under control, demonstrators began throwing concrete rocks up to eight inches in diameter at the officers.

They also were seen setting off fireworks on Crenshaw Boulevard at one point and tried to break into a McDonald's and a shoe store.

Tweeted the L.A. Times' Andrew Blankstein, around 10:30 p.m.: "LAPD commander at the scene says major resources being moved in to Crenshaw area. 'Extraordinary restraint' giving way to 'zero tolerance.'"

Meanwhile, L.A. Mayor Eric Garcetti hit Twitter to praise the organized protesters at the Leimert Park vigil and asked those on Crenshaw to follow their example.

"I commend the prayer rally attendees in Leimert Park for practicing peace," he wrote. "I call on people in the street on Crenshaw to follow their example."

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He added: "We should respect Martin family's call for peace. Unlawful assembly declared. Police are clearing area."

Garcetti held a news conference on the situation around 11 p.m., during which he said 13 people had been arrested.