OAKLAND (CBS SF) — Hundreds of protesters angry with the acquittal of a neighborhood watch volunteer for a fatal shooting in Florida marched through downtown Oakland on Monday night and police have called for mutual aid from other agencies.

The protest is the third in three days in Oakland following the announcement Saturday that George Zimmerman was found not guilty of the murder of 17-year-old Trayvon Martin after a confrontation where he followed Martin believing he was suspicious.

The protest briefly blocked traffic on Interstate Highway 880 and about five people have been arrested, police said. Police could not immediately disclose where and why they were arrested.

The rally began around 6 p.m. in Frank Ogawa Plaza and was initially led by a team of protesters on bicycles—some who decorated their wheels in an Oakland style known as “Scraper Bikes.”

After departing the plaza, protesters marched past Oakland police headquarters, briefly onto the highway before being dispersed by Oakland police and California Highway Patrol officers, and then through Chinatown and toward Lake Merritt.

Police called for assistance from other area law enforcement agencies and there were brief confrontations with officers at several locations, including at the entrance to Interstate Highway 580 near Lake Merritt and at the Rene C. Davidson Courthouse at 12th and Oak streets.

Police warned Monday night that “anyone caught committing acts of vandalism or violent crimes will be subject to arrest.”

There were scattered reports of vandalism—including dumpsters pulled into the street—but not at the level of destruction that happened Saturday night when numerous downtown businesses had windows smashed or were covered in spray paint.

Saturday’s protest in Oakland drew 100 to 150 people, police said. That day, there was also graffiti and broken windows and several garbage cans were lit on fire, but no arrests were made, police said.

Police estimated that 500 people protested in downtown Oakland on Sunday night. Windows were broken and vandals left behind graffiti, police said. One man was arrested.

The city of Oakland said in a statement Monday that police are trying to find video footage of the vandalism in order to arrest the people involved. The statement also said that interim chief met with the owners of most of the vandalized businesses and listened to their concerns while sharing police enforcement plans for Monday night’s protests.

“We recognize the death of Trayvon Martin as a tragic event felt throughout the community. We understand the verdict announcement is an emotional one. We are committed to supporting peaceful assembly and freedom of speech,” the statement, signed by Whent, Mayor Jean Quan and City Administrator Deanna Santana read.

Andrew Neilly, publicist for the Downtown Oakland Association, a community benefit district, said he didn’t know the extent of damage caused by protesters. He said the association is helping business owners with cleanup efforts.

A representative of the Oakland Metropolitan Chamber of Commerce declined to comment on Monday.

In San Francisco, there was a march in the Mission District on Saturday and a peaceful protest in Union Square on Sunday afternoon.

There was also a protest in downtown San Jose on Sunday, with others scheduled Tuesday and Sunday.

San Francisco Bay Area ANSWER organizer Frank Lara earlier on Monday linked the Martin killing to larger issues such as race, police brutality, economic disparity and gentrification.

“It’s such a shocking ruling,” he said.

He said many Bay Area residents can relate to the case because they feel as though they are discriminated against “for being poor, for being black for being Latino.”

He said activists are calling for a federal prosecution in the case while others suggest an economic boycott of Florida.

“We’re sending a political message,” he said. “We have to get the word out about Trayvon Martin.”

Isaac Ontiveros with Oakland-based Critical Resistance said the jury’s decision and the trial process is “an example of how the criminal legal system is flawed.”

Ontiveros said the Bay Area community is “concerned and outraged” because the court system “fails communities, particularly communities of color.”

This is a moment, Ontiveros said, when “people come together in their outrage, in their grief” and there is energy to re-evaluate “the system,” whether that be the courts, police or neighborhood watch groups.

The Richmond Progressive Alliance is standing by the Martin family and urging others to speak out about the racism that the group says fueled the teen’s death and the subsequent acquittal in the trail.

Mike Parker, who is a member of the group, said that through this case, it “becomes evident that the court system in fact doesn’t work for African-Americans.”

He said Martin’s death shows that racism remains an issue to be overcome, despite efforts to become a colorblind nation.

“It can’t be business as usual,” he said.

Political leaders are calling on the U.S. Department of Justice to review the case.

U.S. Sen. Barbara Boxer, D-San Francisco, wrote a letter Monday to Attorney General Eric Holder supporting a federal probe to determine if Martin’s civil rights were violated.

In the letter, Boxer wrote, “I respect the fact that the jury has spoken … but I don’t think this should be the last word.”

On Sunday, the department said in a statement that it is continuing to review evidence in the case to determine whether federal prosecution is appropriate.

Congresswoman Barbara Lee, D-Oakland, also called on federal prosecutors to charge Zimmerman “to further the cause of fairness and justice.”

Zimmerman, 29, had been charged with second-degree murder in Florida state court for the fatal shooting of unarmed Martin. Zimmerman claimed self-defense in the case.

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