VISTA -- The Vista Unified School District has canceled all classes today, citing concerns for student safety after a week of walkouts and student demonstrations that have centered on proposed changes to immigration law, district officials said Thursday.

Across North County on Thursday, there were no reports of student protests.

Vista is the second North County school district this week to close schools over concerns that student walkouts could get ugly today: Oceanside Unified School District closed all seven of its middle and high schools Thursday and today.

Interim Vista Superintendent Darrel Taylor said the decision to close the schools came around 1 p.m. Thursday after the San Diego County Sheriff's Department raised the specter of large protests during today's official state holiday celebrating the late Latino labor leader Cesar Chavez.

"We were presented with some fairly significant information that really told us there could be some trouble (today) with the demonstrators in this area," Taylor said.

The one-day shutdown was a "mutual decision" between school principals, district officials, the school board and law enforcement, according to board Trustee Jim Gibson.

Parents' concerns about lost class time and child care were taken into account, but safety took priority, Taylor said.

"It was not a whimsical decision," he said.

For elementary and middle school students, the closure will slightly extend their spring break, which was to start Monday. High school students will return to class Monday. It is not yet clear if students will have to make up the lost day, Taylor said.

If demonstrations continue next week, Gibson said he will ask his board colleagues if they will support having law enforcement place students who walk out of class into custody for truancy violations.

"As of Monday, as far as I'm concerned, if you're not in class and you're out protesting, then you're truant," Gibson said.

Oceanside schools

Speaking publicly for the first time since hundreds of students walked off of four Oceanside school campuses to protest illegal immigration reforms earlier this week, district Superintendent Ken Noonan said Thursday at a news conference that he closed middle and high schools out of growing concerns that racial tensions could escalate today into violence.

The 21,500-student district has more than 9,400 middle and high school students.

As with Taylor, Noonan said his sources -- police, teachers, parents and students -- suggested that Cesar Chavez Day may be the culminating event of the week's protests.

Oceanside police Chief Frank McCoy, standing with Noonan at Thursday's news conference, said law enforcement officers all across California are "gearing up for potential problems" related to student protests today.

The Oceanside protests began Tuesday when hundreds of Oceanside and El Camino high school students left campus for long protest marches. Oceanside High students tried to stage another protest Wednesday, but were stopped from leaving campus by police officers and sheriff's deputies in riot gear. At one point officers fired pepper-filled plastic balls in front of about 200 students to move them back from a campus gate. Officers also arrested three students on felony assault charges.

Noonan said his decision to close the schools was based solely on "the safety of our students," saying that he feared confrontations between students who left campuses to join protests and those who stayed in school. He said all high schools and middle schools were closed so students would not have a rallying point.

Noonan said closing the campuses appeared to work, noting that there were no reports of student protests Thursday in Oceanside.

"It has maybe taken some of the bite out of this dragon of using the school as a stepping-off place for protests," he said.

Noonan said district officials will create a series of forums to explore the issues that inspired the protests. And on Tuesday, he said, district teachers will lead students in classroom discussions of immigration issues and the protests.

Trustee Emily Wichmann, also present at Thursday's news conference, decried the student protests during school hours and apologized to parents for the disruptions.

"A safe learning environment is not happening," she said, adding that she was especially concerned for students who chose to remain in class. Those students, she said, made the right choice, but have lost educational opportunities because of the actions of a few.

North County is home to about 50,000 high school students. On Tuesday, the height of the protests this week, 1,700 protesters -- or a little more than 3 percent of North County's high school population -- walked out of class.

Financial bite

Although student protesters remained in classes long enough Tuesday and Wednesday to qualify for the daily state funds Oceanside and other districts depend on for operations, the two days of closed schools pose another problem.

Schools are required to provide 180 days of instruction. With this week's closures, Oceanside students may get only 178 days.

Noonan said the district will apply to the state Department of Education for a waiver that will allow it to offer only 178 days of school, although that does not appear likely to happen. That is because state Superintendent of Schools Jack O'Connell announced late Thursday that he would be reluctant to grant waivers for student protests, noting that the state education code generally limits waivers to reasons linked to natural disasters.

Associate Superintendent Robyn Phillips said that if the district doesn't get a waiver then it would add the two days to the end of the school year rather than lose $900,000 in state attendance revenue and fines.

Contact staff writer Philip K. Ireland at (760) 901-4043 or pireland@nctimes.com.