Oakland and San Francisco are among 100 cities across the country that are hosting rallies today in the wake of the acquittal of George Zimmerman in the death of Trayvon Martin.
The rallies come exactly one week after the Florida jury's verdict.
San Francisco's rally was held at 9 a.m. at the Federal Building. It was small and peaceful with no arrests.
Oakland's rally began at noon at Frank Ogawa Plaza. A few hundred gathered to show their support. Oakland Mayor Jean Quan spoke at the rally, but was heckled throughout. Many in the crowd said it was hard to hear what she was saying.
Justin Jones, 17, was one of the Oakland organizers.
Jones, who just graduated from Hercule High School, says he did it to reach out to other young people in the East Bay.
"We’re calling for peace in our communities. Whether in Oakland or Sanford, Florida, We need to end gun violence and especially the youth, we’re trying to get them involved. It’s a modern day civil rights movement," Jones said.
The Rev. Al Sharpton's National Action Networ was the organizer of the national effort. "Justice for Trayvon" events were held from New York to Miami to Los Angeles to Des Moines. Sharpton says he wants the Justice Department to pursue a case.
Zimmerman claimed self-defense after shooting Martin during an altercation. The case has become a flashpoint in national debates over guns, race relations and self-defense laws. Zimmerman identifies as Hispanic. Martin was black.
The Oakland police department said keeping peace on the streets and protecting the safety of Oakland residents and businesses is their top priority.
It's all hands on deck for the police department, who have canceled days off for its officers. The department said it is also ready to call in outside help if needed.
The police department and city leaders said they have studied recent tactics used by vandals who broke windows and tagged buildings throughout the downtown area. They said they have reorganized to respond to situations should they arise this weekend.
"Although we don’t anticipate problems to occur, in the event that the demonstrations and protests become unlawful, the Oakland Police Department is prepared to swiftly address any criminal behavior that would damage property or jeopardize the safety of the public or police officers. Individuals engaging in such behavior are subject to arrest and prosecution," a city press release read.
The Oakland police department was heavily criticized after the chief of police admitted police were not prepared for last Saturday's protest. Chief Sean Whent said they didn't even know the jury was deliberating on the weekend.
"We are disappointed that this week a small number of protesters have dishonored the memory of Trayvon Martin and his family by engaging in violence and vandalism," said Mayor Jean Quan. "They have endangered innocent people, damaged locally owned businesses that provide jobs for Oaklanders, and hurt our growing economy."
Friday night, about 250 protesters gathered and marched from the Oakland Federal Building to the Fruitvale BART station. Many voiced their anger over the not guilty verdict.
Oakland police were out in force Friday night and said there were no problems, including no reports of vandalism.
Police said they are using every strategy they can think of to keep the city safe this weekend
Below is raw video from the San Francisco event:
View more videos at: http://nbcbayarea.com.