Al Sharpton, accompanied by leading ministers of the black community, calls for a "national Justice for Trayvon Day," featuring rallies in 100 cities across the U.S. in the wake of the acquittal of George Zimmerman.

A day after violent protests over the acquittal of George Zimmerman in the death of Trayvon Martin, city leaders and activists urged peace even as a leading civil rights activist said demonstrations will continue all summer – starting with vigils in 100 cities on Saturday.

“We don’t want anyone hurt. We don’t want any cars broken into, and we don’t want any damages to business,” Eddie Jones of the Los Angeles Civil Rights Association told NBCLosAngeles.com.

L.A. Mayor Eric Garcetti and LAPD Chief Charlie Beck called for calm in a Tuesday afternoon news conference after a second night of unrest in the city in which 14 people were arrested, most for failing to disperse after people clashed with police, attacked a news crew and threw rocks.

LAPD will not tolerate vandalizing cars, blocking traffic or attacking innocent people. Let your message be heard peacefully #Protestinpeace — Chief Charlie Beck (@LAPDChiefBeck) July 16, 2013

Beck said lawbreakers wouldn’t be tolerated. "You come here again tonight, you will go to jail," he said.

"We are calling on people to practice peace," Garcetti said, “to not let the dialogue sparked by Martin's death be silenced by any violence."

The warnings and pleas appeared to have been effective. A peaceful crowd of about 200 marched along downtown streets Tuesday evening, blocking traffic, the Los Angeles Times reported on its website. But the group had dispersed by 8:30 p.m. (11:30 p.m. ET), the Times reported.

City leaders in Oakland, Calif., also called for protesters to be peaceful after a Monday night demonstration sank into chaos. Nine people were arrested and several businesses were vandalized. A businessman dining in a restaurant that was vandalized said a protester assaulted a waiter.

Interim Oakland Police Chief Sean Whent said Tuesday that his department was caught off guard and added no staffing ahead of the protests that erupted Saturday because he was unaware that the Zimmerman jury was deliberating on the weekend, NBCBayArea.com reported.

Meanwhile, the Rev. Al Sharpton announced vigils across the country that will be followed by marches in Tallahassee, Fla., and Washington, D.C.

“Florida will be the battleground of a new civil rights movement,” Sharpton said during a news conference with other clergy outside the Justice Department headquarters.

“We are not having a two- or three-day anger fit,” said Sharpton,who is president of the National Action Network and also hosts a show on MSNBC. “This is a movement for social justice.”

Sharpton said the nationwide action has two goals: urging the Justice Department to move forward with a civil-rights probe of Zimmerman and repealing “Stand Your Ground” self-defense laws that some say made it difficult to win a conviction in the case.

Rallies and vigils have been held by Martin supporters in major cities since a Florida jury found Zimmerman not guilty on Saturday night. They have been mostly peaceful, though 14 people were arrested Monday night in Los Angeles after a gathering descended into chaos with some people throwing rocks, attacking people and clashing with police, NBCLosAngeles.com reported.

Sharpton also urged all protesters to remain peaceful, saying Martin’s name should not be “smeared with reckless violence.”

Fourteen people were arrested in Los Angeles after another night of protests over the acquittal of George Zimmerman over the weekend, putting the LAPD on tactical alert.

At the same time, he struck a fiery tone, saying, “On Saturday night with the verdict we lost the battle, but the war is not over and we intend to fight.”

The first action will be Saturday, when Martin supporters will gather for an hour in front of federal buildings and courthouses in 100 cities “calling on the Department of Justice to resume aggressively a civil rights investigation in this matter.”

The Justice Department launched a probe three weeks after the Feb. 26, 2012, shooting in Sanford, Fla., and it remains open. While Attorney General Eric Holder said this week that Martin’s death was “unnecessary,” many legal experts doubt that the feds will bring hate crime charges against Zimmerman.

Zimmerman is of white and Hispanic descent and Martin was black, but state prosecutors did not make race a major issue during the trial. Defense lawyer Mark O’Mara has said race was not a factor in the confrontation and that if Zimmerman had been black, he never would have been arrested.

The volunteer neighborhood watchman, who pleaded not guilty to second-degree murder, claimed he shot the unarmed teen in self-defense after being attacked on a dark rainy night in the gated community.

Jae C. Hong / AP A Trayvon Martin supporter confronts a Los Angles police officer during a demonstration in reaction to the acquittal of neighborhood watch volunteer George Zimmerman on Monday, July 15, in Los Angeles.

While Zimmerman did not invoke Florida’s “Stand Your Ground” law and ask for an immunity hearing before the trial, the jury’s instructions borrowed language from the law, specifying that if “he was attacked in any place where he had a right to be, he had no duty to retreat and had the right to stand his ground and meet force with force.”

Sharpton said civil rights leaders will convene in Miami on July 23, 24 and 25 to plan a drive against “Stand Your Ground” laws in Florida and other states and organize a major march in Tallahassee, the capital.

“We will be in Florida en masse,” he said.

On Aug. 24, there will be a march on Washington and Sharpton said corporations that support “Stand Your Ground” laws will be economically targeted.

“As long as ‘Stand Your Ground’ is on the books, we will continue to have the potential of other Trayvon Martins,” he said.

One of the jurors told CNN on Monday that no one on the panel believed race played a part in the shooting and she had “no doubt” that Zimmerman feared for his life and acted in self-defense.

Juror B37 recounted to CNN’s Anderson Cooper some of the behind-the-scene discussions that took place during jury deliberations. The woman said three members of the jury not did want to acquit Zimmerman when they first began discussing the verdict, but changed their minds over the course of deliberations.

But late Tuesday, four out of the five other jurors released a statement asking for privacy and saying Juror 37’s public comments “were her own, and not in any way representative of the jurors listed below.”

“Serving on this jury has been a highly emotional and physically draining experience for each of us,” the four women, identified only by their juror number, said in the statement. “The death of a teenager weighed heavily on our hearts but in the end we did what the law required us to do.”



NBC News' Tom Winter contributed to this report

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