(NEW YORK) -- Several protesters were arrested this weekend when demonstrators expressed their anger at the acquittal of George Zimmerman in rallies across the nation, although most of the events were peaceful with marchers wearing hoodies, carrying signs and chanting "Justice for Trayvon Martin."
The largest rally took place Sunday night in New York City and lasted until early Monday morning. Thousands of marchers spontaneously moved through different Manhattan neighborhoods and shut down traffic from Union Square to Times Square. A group of the protesters made their way to the Bronx Criminal Courthouse near Yankee Stadium at around 3 a.m.
The event started as a peaceful march, but protesters began to get rowdy, and police made a handful of arrests after bottles were thrown at officers, ABC News station WABC-TV reported.
Police in Oakland, Calif., declared an unlawful assembly with reports of demonstrators throwing rocks and bottles at police and even attacking journalists, according to ABC News station KGO-TV. Police estimates put the crowd at about 200 people at its height Sunday.
In Los Angeles, hundreds walked on Interstate 10 on Sunday, causing police to close down a main artery for traffic. At a nearby street corner, a crowd threw rocks and batteries at officers, prompting them to fire beanbag rounds, Police Cmdr. Andrew Smith told ABC News station KABC-TV.
Zimmerman, 29, was found not guilty in the death of Trayvon Martin late Saturday night. Zimmerman was accused of second-degree murder for shooting Martin, 17, on Feb. 26, 2012, in Sanford, Fla. Zimmerman claimed self-defense.
The trial's "not guilty" verdict has ignited a national debate that extends beyond Martin to issues of racism, profiling and equal justice.
In Sanford, the Rev. Lowman Oliver at the Baptist Church urged people to speak out against the verdict.
"It is a righteous thing. It is that which is good and that which is evil. Now you choose which side you're going to be on," Oliver said Sunday. "But if you sit still and do nothing, you have chose on the evil side. Get up from where you are and we got to get together and do something about it."
Civil rights activist Rev. Jesse Jackson said people need to keep the pressure on for justice.
"They'll be a civil lawsuit filed that we should rally around," Jackson said. "We can all urge the Department of Justice to rally around and they must."
The U.S. Justice Department has been conducting its own investigation into whether the shooting was motivated by racial pretense -- meaning Zimmerman could be charged with a federal hate crime even though he was acquitted in state court -- and could also take Zimmerman to trial.
The DOJ released a statement post-verdict saying their investigation was ongoing.
"The department continues to evaluate the evidence generated during the federal investigation, as well as the evidence and testimony from the state trial," a spokesman for the U.S. Department of Justice said in a statement Saturday.
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