Police said at least 130 demonstrators who refused to disperse during a Los Angeles protest were arrested, while 33 people were detained in Oakland following a march that deteriorated into unrest and vandalism.
In Los Angeles, about 200 or 300 largely peaceful demonstrators crisscrossed downtown streets for several hours in the afternoon and evening over a decision not to bring criminal charges against a Ferguson policeman for killing a black man.
But later some of the protesters were stopped by a phalanx of riot-clad police near the Central Library.
Lt. Andy Neiman said an unlawful assembly was declared after some marchers began walking in the street and disrupting traffic. They were ordered to disperse but instead reformed, with police trying to corral them.
Neiman said 130 protesters were arrested, with most appearing calm as they were handcuffed with plastic bands and walked to waiting Sheriff's Department buses.
Meanwhile, Oakland police spokeswoman Johnna Watson said the 33 arrests there came after a march by about 100 people through Oakland streets.
She said that later small groups began moving through the streets with some vandalizing property, mainly breaking windows.
Most of the protesters had dispersed but shortly before midnight Watson said that there was still a very small group that police were monitoring.
On Monday and Tuesday, some demonstrators in Oakland vandalized businesses and blocked freeways to protest the decision not to indict Officer Darren Wilson in the Aug. 9 fatal shooting of 18-year-old Michael Brown.
During the demonstration Wednesday in Los Angeles, demonstrators had marched to a federal building and police headquarters but they were turned away by lines of police after heading toward the county jail and then the Staples Center arena, where the Los Angeles Lakers were playing.
"The system is wrong," demonstrator Jovan Brown told KCAL-TV. "We're trying to let everybody know if we come together as a people and unite, we can change it."
There was a brief, tense confrontation where a handful of demonstrators screamed at officers, who held raised batons. One officer struck a woman who had moved forward, and another shoved a protester.
Finally, squads of police boxed in and began arresting around 60 remaining protesters for failure to disperse, Neiman said.
Most of those arrested were expected to be released after posting $500 bail for the misdemeanor. However, those unable to pay the bail could remain jailed through the Thanksgiving weekend pending scheduled Monday court hearings, authorities said.
Earlier Wednesday, nine people were arrested after they sat down in a bus lane on U.S. 101 near downtown during one of the busiest driving days of the year.
There were smaller, peaceful protests in other communities, including San Diego and Riverside.
More than 300 protesters have been arrested over the past three days by Los Angeles police and California Highway Patrol officers.