Last Updated 3:42 p.m. ET
Video of a tense standoff between police and Occupy demonstrators at the University of California, Davis shows an officer using pepper spray on a group of protesters who appear to be sitting passively on the ground with their arms interlocked - action the university chancellor called "chilling to us all."
Several videos, which were posted on YouTube, were shot Friday as police moved in on a tent encampment on the campus.
In the video, an officer displays a bottle before spraying its contents on the seated protesters in a sweeping motion, walking back and forth.
Most of the protesters have their heads down, but at least one is hit in the face.
Some members of a crowd gathered at the scene scream and cry out, then chant, "Shame on You," as the protesters are arrested. The officers retreat minutes later with helmets on and batons drawn.
"Yesterday was not a day that would make anyone on our campus proud," UC Davis chancellor Linda Katehi wrote in response to the pepper-spraying video.
It's not clear from the video what agency the officer who used the pepper spray represents. Officers from UC Davis and other UC campuses as well as the city of Davis responded to the protest, according to Annette Spicuzza, UC Davis police chief. Davis is about 80 miles north of San Francisco.
Spicuzza told the Sacramento Bee that police used the pepper spray after they were surrounded. Protesters were warned repeatedly beforehand that force would be used if they didn't move, she said.
"There was no way out of that circle," Spicuzza said. "They were cutting the officers off from their support. It's a very volatile situation."
The tents went up on Thursday, and protesters were warned on Friday morning that they had until 3 p.m. to take them down or they would be removed.
On Saturday Chancellor Katehi announced the formation of a task force comprised of faculty, students and staff to review the week's events and design a process to avoid such confrontations in the future.
In a letter to the UC Davis community Katehi wrote that protests on campus during the past week had been peaceful, and that some students and non-students who had erected tents on campus had agreed to remove them, as per university policy. But when several students refused to take down 25 tents, police moved in.
"The use of pepper spray as shown on the video is chilling to us all, and raises many questions about how best to handle situations like this," Katehi wrote.
"While the university is trying to ensure the safety and health of all members of our community, we must ensure our strategies to gain compliance are fair and reasonable and do not lead to mistreatment."
In other "Occupy" developments:
Seattle, Wash.: An 84-year-old woman who was pepper sprayed this week at an Occupy Seattle protest said the national attention she received can help the movement's cause. Dorli Rainey addressed a crowd of about 100 people Friday afternoon who had marched to police headquarters downtown.
Rainey was at an Occupy Seattle event Tuesday evening when police used pepper spray on the protesters. A picture of Rainey taken immediately after she was hit by the chemical irritant was published worldwide. Police say the group Rainey was in was blocking traffic and ignored orders to disperse.
Los Angeles, Calif.: Police arrested 14 Occupy UCLA protesters, all but one of them students, on campus, breaking up an encampment of 25 tents. University spokesman Steve Ritea said about 40 protesters left after police ordered the crowd to disperse at about 5:15 a.m. Friday.
In videos posted to a Facebook page for Occupy UCLA early Friday morning, protesters sang and gave impassioned speeches to the surrounding police force about income disparity and financial barriers to higher education. Those arrested were cited for failure to disperse and released. Ritea said the protests follow repeated tuition increases in recent years.
Indianapolis, Ind.: State officials have cleared most of the Occupy Indy encampment from the Indiana Statehouse lawn. Department of Administration Commissioner Rob Wynkoop said that the small band of protesters had cleared most of its camping gear on Thursday but that more items were added overnight and he ordered the site cleared before dawn Friday. Protester Greg Lambert of Indianapolis said he and others are "furious."
New York: Mayor Michael Bloomberg is arguing that several thousand protesters who marched over the Brooklyn Bridge during Thursday's "Day of Action" are not representative of Occupy Wall Street.
The protest took place amid demonstrations nationwide marking the two-month anniversary of the movement that began with Occupy Wall Street.
In his weekly WOR Radio show Friday the mayor said that "a vast percentage" of the marchers were union members who "had organized signs and leadership." Bloomberg said the protest "was just an opportunity for a bunch of unions to complain or to protest, or whatever they want to do."
Nashville, Tenn.: A group of Occupy Nashville protesters disrupted a discussion with former Defense Secretary Donald Rumsfeld about his memoir, "Known and Unknown," and were ejected by security.
The group said in a press release that an anonymous donor purchased four $125-a-plate dinners that allowed protesters to enter the Thursday night event, which was sponsored by the conservative Washington think tank the Heritage Foundation at a downtown Nashville hotel. They mingled with the crowd before standing up, one by one, and accusing Rumsfeld of being a war criminal. They also suggested Rumsfeld should go outside and submit to a citizen's arrest.
Heritage spokesman Matthew Streit confirmed that four protesters caused what he called a "brief interruption" of the discussion.
Outside the hotel where Rumsfeld was appearing, Occupy protesters noticed a van with blacked-out windows marked to appear like a van from Nashville Electric Service, but a call to NES revealed it was not one of theirs. Computers screens were visible through the front window, and what appeared to be a camera was mounted on top, but the driver had disappeared into the back, leaving the engine running.
In video posted by Occupy Nashville, protesters heckled the van's occupant(s), and called the police. (It was parked illegally.) When police came to inquire, the van sped away.
Boston: The nonprofit organization that oversees the site of the Occupy Boston encampment wants the protesters out. The chairwoman of the Rose Kennedy Greenway Conservancy's board says in a Tuesday letter to Mayor Thomas Menino that demonstrators have prevented the general public from enjoying Dewey Square Park and forced the cancellation of other events scheduled for the site, including an Oct. 15 food festival.
The Boston Globe reports that Chairwoman Georgia Murray also wrote that sanitary conditions have worsened, farmers selling food in the area have seen sales decline because of "noise, odors, and interference" from demonstrators, and the camp has shown "disturbing signs of drug dealing."
Portland, Me.: Police have charged two Occupy Maine activists with assault and arrested a third on a disorderly conduct charge in two separate disturbances at an encampment at a Portland park. Police say 45-year-old Alan Porter was hit in the head with a hammer Friday morning after he started drumming to awaken the other occupants. One 34-year-old man was charged with aggravated assault, and another 34-year-old man was given a summons for assault for allegedly choking Porter.
St. Louis, Mo.: Occupy St. Louis said the 14 protesters arrested near the entrance to a Mississippi River bridge are out of jail. Police made the arrests without incident late Thursday afternoon as hundreds of protesters tried to block the entrance to the Martin Luther King Bridge.
Eugene, Ore.: As many as 300 Occupy Eugene protesters spent an afternoon demonstrating at bank offices, and 17 were arrested. Members of the group told police in advance Thursday they were planning civil disobedience, and the police told bankers they wouldn't move against the protesters unless people refused to move on when asked. The Eugene Register-Guard reported that arrests, mostly for trespassing, were made at two bank offices, Bank of America and Chase, but not at three others. One person was charged with resisting arrest. Most of the banks managed to carry on at least some customer business during the protest.
Philadelphia, Pa.: Police arrested about a dozen members of the Occupy Philadelphia movement who were protesting at a bank downtown. The protesters refused to leave the Wells Fargo branch on Friday evening and were arrested peacefully. About two dozen members of Occupy Philadelphia were arrested on Thursday during a protest on the Market Street bridge.
Austin, Texas: Police said five people have been arrested after chaining themselves to a tree and refusing to leave during an Occupy Austin protest.