SAN FRANCISCO >> Two University of California, Davis police officers involved in the pepper spraying of seated protesters were placed on administrative leave Sunday, as the school’s chancellor said she was accelerating an investigation of the incident.

UC Davis Chancellor Linda Katehi said she has been inundated with reaction from alumni, staff, students and faculty over the incident Friday in which a riot gear-clad officer fires pepper spray on a line of sitting demonstrators. The protesters flinch and cover their faces but remain passive with their arms interlocked as onlookers shriek and scream out for the officer to stop.

The officers who were placed on leave have not been identified. In a news release, the university said, "Videos taken during Friday’s arrests showed that the two officers used pepper spray on peacefully seated students."

The faculty association on Saturday called for Katehi’s resignation after video of the incident was circulated widely on YouTube, Facebook and Twitter on Saturday, saying in a letter there had been a "gross failure of leadership."

Katehi has resisted calls for her to quit, vowing instead to rigorously investigate the incident during which 10 protesters were arrested.

"I am deeply saddened that this happened on our campus, and as chancellor, I take full responsibility for the incident," Katehi said in a statement Sunday. "However, I pledge to take the actions needed to ensure that this does not happen again. I feel very sorry for the harm our students were subjected to and I vow to work tirelessly to make the campus a more welcoming and safe place."

Katehi also set a 30-day deadline for a task force investigating the incident to issue its report. The task force will be comprised of students, staff and faculty, Katehi said, and will be chosen this week.

As the video spread of an officer in riot gear blasting pepper spray into the faces of seated protesters at a northern California university, outrage came quickly — followed almost as quickly by defense from police and calls for the chancellor’s resignation.

However, a law enforcement official who watched the clip called the use of force "fairly standard police procedure."

The protest was held in support of the overall Occupy Wall Street movement and in solidarity with protesters at the University of California, Berkeley who were jabbed by police with batons on Nov. 9.

Charles J. Kelly, a former Baltimore Police Department lieutenant who wrote the department’s use of force guidelines, said pepper spray is a "compliance tool" that can be used on subjects who do not resist, and is preferable to simply lifting protesters.

"When you start picking up human bodies, you risk hurting them," Kelly said. "Bodies don’t have handles on them."

After reviewing the video, Kelly said he observed at least two cases of "active resistance" from protesters. In one instance, a woman pulls her arm back from an officer. In the second instance, a protester curls into a ball. Each of those actions could have warranted more force, including baton strikes and pressure-point techniques.

"What I’m looking at is fairly standard police procedure," Kelly said.

Images of police actions have served to galvanize support during the Occupy Wall Street movement, from the clash between protesters and police in Oakland last month that left an Iraq War veteran with serious injuries to more recent skirmishes in New York City, San Diego, Denver and Portland, Ore.

Some of the most notorious instances went viral online, including the use of pepper spray on an 84-year-old activist in Seattle and a group of women in New York. Seattle’s mayor apologized to the activist, and the New York Police Department official shown using pepper spray on the group of women lost 10 vacation days after an internal review.

In the video of the UC Davis protest, the officer, a member of the university police force, displays a bottle before spraying its contents on the seated protesters in a sweeping motion while walking back and forth. Most of the protesters have their heads down, but several were hit directly in the face.

Some members of a crowd gathered at the scene scream and cry out. The crowd then chants, "Shame on You," as the protesters on the ground are led away. The officers retreat minutes later with helmets on and batons drawn.

Nine students hit by pepper spray were treated at the scene, two were taken to hospitals and later released, university officials said.

UC Davis Police Chief Annette Spicuzza has said the decision to use pepper spray was made at the scene.

"The students had encircled the officers," she said Saturday. "They needed to exit. They were looking to leave but were unable to get out."

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Associated Press reporters Sudhin Thanawala in San Francisco, Nigel Duara in Portland, Ore., and Meghan Barr in New York City contributed.

Associated Press reporters Nigel Duara in Portland, Ore., and Meghan Barr in New York City contributed.