Los Angeles, California (CNN) -- Students were occupying buildings Friday on several campuses of the University of California system in protest of a 32 percent tuition hike.

Students had take over portions of buildings on campuses in Los Angeles, Berkeley, Santa Cruz and Davis late Thursday, and at least some were still occupied Friday morning.

Student organizers said they would escalate their protests after the system's regents approved the tuition hike during a meeting Thursday on the UCLA campus.

University officials said the $505 million to be raised by the tuition increases is needed to prevent even deeper cuts than those already made because of California's persistent financial crisis.

Protesting students said the hike will hurt working and middle-class students who benefit from state-funded education.

On the Santa Cruz campus, where building occupations began last week at a library, about 100 students staged a sit-in in the second-floor lobby of Kerr Hall soon after hearing of the tuition hike's approval, according to UC Santa Cruz Provost David Kliger.

Such action, he said, "does little more than divert precious resources while denying others their rightful access to campus facilities and services."

His campus suffered $50 million in state budget cuts this year, Kliger said.

On Friday morning, UC Berkeley students occupied the second floor of Wheeler Hall, UC Berkeley spokeswoman Janet Gilmore said. Campus police broke through a barricade of furniture and office equipment on the ground floor and arrested three students, Gilmore said.

She said she did not know how many students remained in the building, which was closed. A small number of classes were canceled, Gilmore said.

Authorities arrested dozens of angry students at the Davis campus late Thursday after they refused to vacate the school's administration building.

The Davis Police Department and deputies from the Yolo County Sheriff's Department took 52 students into custody, according to UC Davis spokeswoman Claudia Morain.

The arrests at Mrak Hall administration came about four hours after the usual 5 p.m. PT closing time. At one point, as many as 150 students were at the building protesting the tuition increase, Morain said.

 UCLA's Campbell Hall was occupied for several hours Thursday evening, a school spokesman said.

The takeover was not planned or sanctioned by the main protest organizer -- the United States Student Association, according to Gabby Madriz, a representative for the group.

The same building was briefly occupied Wednesday night by several dozen student protesters, according to a UCLA news release. The building was the site of the 1969 shooting deaths of two Black Panther Party members during an internal dispute, the statement said.

The UCLA campus was the scene of the largest and loudest demonstrations Thursday.

"We're fired up. Can't take it no more," students chanted as they marched and waved signs at UCLA. "Education only for the rich," one sign read.

Some faculty members and campus workers -- saying they're worried about possible furloughs and layoffs -- joined the students.

"Stop cuts in education and research," a sign carried by a teacher said.

After the regents voted, students rushed to parking decks to stage a sit-in to block regents' vehicles from leaving. Campus police and California Highway Patrol officers in riot gear stood nearby.

As one regent member walked out, students lining his path shouted, "Shame on you, shame on you."

The situation ended without incident as students gradually left the scene.

University executives told the regents the fee hikes are needed because they've already made deep spending cuts in the past two years -- cuts forced by the state budget.

About 26 percent of the $20 billion spent each year by the system comes from the state's general fund coupled with tuition and fees paid by students, according to a summary on the regents' Web site.

The first tuition hike, which will take effect in January, will cost undergraduate students an additional $585 a semester. The second increase will kick in next fall, raising tuition another $1,344, the regents said.

The fee increases are to be balanced by a raise in "the level of financial assistance for needy low- and middle-income students," according to the Board of Regents.

The tuition hike is expected to raise $505 million for the university system, and about $175 million of that money is to go toward student financial aid, the board said.