A group of about 200 people, at times appearing outnumbered by police, marched through the streets of downtown Los Angeles between City Hall and police headquarters, briefly blocking traffic but remaining peaceful. They were flanked by officers on bicycles and on foot but did not challenge or provoke them.
Another rally at a park near LA's Crenshaw District, which saw most of the violence and vandalism Monday night, was nearly as subdued.
Police Chief Charlie Beck and Mayor Eric Garcetti, who took office barely two weeks ago, said peaceful protests were welcome but violence wouldn't be tolerated. Beck vowed that anyone committing violence would be arrested.
"Your actions ... will reduce the power of the message of this community, and that is wrong. That is a shameful act," he said.
Los Angeles and Oakland have been flashpoints for violent reactions to Saturday's acquittal of Zimmerman in the death of Trayvon Martin.
In Los Angeles, 14 people were arrested Monday night after about 150 people split from a peaceful demonstration at a park, running through the streets, jumping on cars, trying to break store windows and punching bystanders.
A reporter and photographer for TV stations KCBS and KCAL also were assaulted and transported to a hospital with minor injuries. A police officer was punched in the chest Sunday, and a 24-year-old man, Brandon Bell, was charged Tuesday with battery and resisting arrest.
Deputy Chief Bob Green, who heads the LAPD's South Bureau, said officers were pelted with rocks as they stood by monitoring the protest. He blamed the incidents on "knuckleheads" from outside the area who are trying to provoke a confrontation with police.
In San Francisco, a peaceful crowd that gathered in the evening at City Hall listened to speeches by NAACP leaders and sang "We Shall Overcome."
A few dozen demonstrators watched closely by police in riot gear gathered at Oakland City Hall. A night earlier, protesters left a City Hall gathering and briefly blocked Interstate 880. They also tried to march onto Interstate 580, threw fireworks and assaulted a restaurant waiter with a hammer. Oakland police made nine arrests for crimes including assault with a deadly weapon and vandalism.
Los Angeles officials are sensitive to images of unrest in a city where the 1965 Watts Riots resulted in 34 deaths, and 1992 violence following the acquittal of four white officers in the beating of black motorist Rodney King left 55 people dead and thousands injured.
The LAPD has spent years building relationships in the black community, and is working with African-American leaders to head off more serious violence. More than 300 police officers responded to the Crenshaw demonstration. They were intentionally slow to directly engage protesters, to allow a peaceful end to the demonstration.
The department's response demonstrated the progress that's been made, said Earl Ofari Hutchinson, president of the south LA-based community activist group Los Angeles Urban Policy Roundtable.
"They didn't wade in with stun guns and billy clubs, shooting up the joint, which might have happened 20 years ago," Hutchinson said. "I think that's a sign they've learned a few things."
Los Angeles Police Commissioner John Mack, a former president of the Los Angeles Urban League, said the public needs to differentiate between the troublemakers and the peaceful demonstrators.
"It's important we don't get carried away and get so focused on the few, who in my opinion clearly were not a part of the organized group and had their own agenda," Mack said. "Quite frankly, I'm not so sure that all of them even cared about Trayvon Martin."
Associated Press writer Terry Collins contributed to this report. Tami Abdollah can be reached at http://www.twitter.com/latams