Undeterred by chilly weather or the Christmas holiday, dozens of antipolice demonstrators marched through downtown Oakland on Thursday evening — some smashing windows of businesses in Jack London Square, throwing bottles, and even tearing ornaments and lights from a large Christmas tree —in the latest round of protests against what they see as police violence toward minorities.

The action on Christmas night, dubbed “No Time Off” by organizers, began around 5 p.m. at Broadway and 14th Street at Frank H. Ogawa Plaza and wound down around 7:30 p.m. The protest followed weeks of marches around the Bay Area after grand juries in Missouri and New York opted not to indict white police officers in the killings of unarmed black men.

“We are committed to ending deeply institutional racism in police departments,” said Jessica Karadi, 28, of Richmond, who was among the few protesters willing to speak with the media. Most wanted to express their messages themselves through signs like the one Karadi was carrying: “End the Police State.”

“We’ll not stop marching because it’s Christmas,” she said of the group being trailed by seven police cruisers.

Only when the marchers walked by police headquarters on Seventh Street did police in riot gear make a brief appearance. But the demonstrators passed them by.

Leading the pack of 50 or so marchers was a group carrying a banner reading, “Justice for O’Shaine Evans. No Justice. No Peace,” referring to the 26-year-old Oakland man shot and killed by San Francisco police in October. The officer who shot Evans seven times said the man had aimed a gun at him.

“What do we want? Justice! When do we want it? Now!” the protesters cried. Another chant was aimed specifically at the police: “F.T.P.! F— the police!”

California Highway Patrol officers also blocked freeway on-ramps.

As the marchers swept through Jack London Square, they shattered the windows of a BevMo and a Subway restaurant, said a witness who declined to give his name, saying he feared for his safety.

After breaking those windows, “they tried to break the windows of the Ben & Jerry’s” but weren’t able to, said the man, adding that he went to Jack London Square “to watch 'Unbroken,’ ironically,” he said.

Marchers also threw a bottle that hit a Chronicle photographer, injuring her hand. And in a decidedly un-holiday spirit, some protesters vandalized Jack London Square’s large Christmas tree.

On Dec. 15, police arrested a dozen people during a protest at the Oakland Police Administration Building at Seventh Street and Broadway. Demonstrators chained themselves to four entrances while one man climbed up a flagpole outside the building and hung a sign reading, “Black lives matter.”

That protest remained nonviolent, but other protests in the East Bay have been marred by violence, vandalism and the destruction of property. At times, police have deployed tear gas to scatter crowds of hundreds. Protesters have blocked East Bay interstates, while outlying members of the protest set fires and smashed windows of businesses in Oakland, Berkeley and Emeryville. Some demonstrators have been recorded on video attacking fellow marchers who were pleading for nonviolence.

Protests cooled off around the Bay Area after two New York police officers were shot and killed Saturday by Ismaaiyl Brinsley, who boasted about wanting to kill police before the slayings. After the executions, Brinsley ran to a nearby subway platform where he shot himself in the head.

Bay Area police union leaders on Wednesday acknowledged demonstrators’ right to protest but decried verbal attacks on police and called for a conversation between both sides. Some protest organizers, though, said police needed to recognize a problem before any constructive dialogue could take place.

Evan Sernoffsky is a San Francisco Chronicle staff writer. E-mail: esernoffsky@sfchronicle.com Twitter: @EvanSernoffsky