10,000 Students Protest Prop. 187 : Immigration: Walkouts in the Valley and elsewhere are largest yet showing campus opposition to initiative. Teen-agers are mostly peaceful, with 12 arrests reported.

Defying calls from campaign leaders and principals to stay in school and ignoring the unwelcoming weather, more than 10,000 teen-agers walked off middle and high school campuses around Los Angeles on Wednesday in the largest showing yet of student opposition to Proposition 187.

From the lawn at the Federal Building in Westwood to a side street in South-Central, from the Van Nuys Civic Center to the steps of City Hall, the teen-agers were mostly peaceful as they marched in rivers of plaid, T-shirts and jeans under the watchful eyes of Los Angeles police, who called a citywide tactical alert.

In the latest of a series of such demonstrations that have been growing for two weeks, there was only one report of significant trouble--in Compton, where 12 arrests were made after reports of rock-throwing, window-breaking and vandalism on police cars.

“Everything was fine until they . . . got unruly and started running in front of cars,” LAPD Traffic Officer Matthew Klein said as he held curious neighbors back from a corralled group of middle-school students on East 48th Street in South-Central Los Angeles.

Most marchers, who came from more than 30 Los Angeles Unified School District campuses, left their school grounds before noon and many were back at school, or at home, before the dismissal bell. Most of the demonstrators appeared to be Latinos.

In the San Fernando Valley, more than 2,000 students from 14 schools took to the streets, scaling fences to escape from closed campuses and join marchers from other schools.

Although the students might not have been organized, almost everyone else was. Los Angeles police were deployed throughout the Valley and escorted the marchers--some drenched from the morning rain--through busy intersections. School district administrators used cellular phones to dispatch school buses to pick up students after the demonstrations, and some administrators cut short break periods so that students would spend more time inside classrooms.

“We’re here to tell people to vote against 187,” said Felix Jimenez, a Grant High student who organized a Van Nuys protest and urged his classmates to be peaceful. “Grant High School students, remember, we made a promise that we were going to behave. Let’s show everyone that we are proud of who we are.”

At the Van Nuys Civic Center, where about 500 students from Birmingham, Grant and Van Nuys high schools and Sepulveda Middle School converged, students were given anti-187 signs produced by Californians United Against Prop. 187, and listing a 900 number for information that costs $5 a call.

Jimenez, 19, said he photocopied the signs on his own and handed them out.

About 600 students from Taft High in Woodland Hills walked off campus after a mid-morning break--the first protest by Taft students--and marched for several miles before ending up back in class by mid-afternoon. Police and school administrators, escorting the students back to school, said they did not want a repeat of last week when thousands of youths marched through Van Nuys streets, leading to scattered fighting and vandalism.

School administrators from San Fernando to Van Nuys tried to keep students on campus by locking gates, but many students scaled fences or cut holes in chain-link fences. Other administrators were unable to block the large number of students leaving.

“We went one way, they went another,” said Wayne Tyra, principal at Fulton Middle School in Van Nuys, where about 30 students left campus. “They jumped over a fence and disappeared.”

At Sun Valley Middle School, about 1,700 students gathered on the playing field to form a pattern that read “No on 187,” much like a marching band in formation.

Several Taft teachers said they were proud of the students for caring about the issue and making a public statement.

“One student . . . someone who never talks in class, came to me after the walkout and said: “Mr. Jacobs, did you come to the rally? I was a speaker!” said Errol Jacobs, a Taft English teacher. “I was amazed. I told him I was very proud of him and I was.”

As with previous student protests, there was no indication that the widespread walkouts had been organized by the formal anti-187 campaigns. Most of the official groups had joined teachers and parents in urging students to stay in school and stage sit-ins or political forums.

Wednesday’s walkouts appeared to be the result of a variety of efforts to coordinate the sporadic school protests that have flared up in recent weeks.

On radio talk shows, activists with the One Stop Immigration and Educational Center, who organized a major Downtown march last month, had called for a countywide school walkout Wednesday. At the behest of worried parents, the center rescinded its call.

But, fueled by media reports and continued support for walkouts by a new statewide anti-187 student coalition, individual campus leaders pushed forward with their preparations.

During Wednesday’s protests, it became clear that some officials and more established groups have jumped on the student-enthusiasm bandwagon:

* At Los Angeles City Hall, council members Richard Alarcon and Jackie Goldberg left a meeting to address the students milling outside. At a protest rally in Long Beach, Dist. Atty. Gil Garcetti compared Proposition 187 to the internment of Japanese-Americans during World War II.

* When an estimated 700 University High School students reached the Federal Building around 10 a.m., the Peace and Freedom Party candidate for governor, Gloria La Riva, greeted them with sound equipment and a ready speech.

* Literature passed out at City Hall, where about 1,000 teen-agers from nearby Belmont High and the Downtown Business High School joined forces, included flyers from organized labor and the Revolutionary Communist Youth Brigade encouraging walkouts.

* And, accompanying 200 Jordan High School students on their trek through Southeast Los Angeles were five members of the Latin American Truckers Assn., who passed out flyers demanding the right of the United Transport Workers Union of America to organize and bargain with the Santa Fe Railway Co.

The rowdiest and longest demonstration took place in Compton, where at least three groups from several schools--each containing 300 to 400 students and others--marched through the city beginning at 8 a.m., some of them throwing rocks, eggs and bottles at police officers.

Demonstrators broke store windows, frightened store employees, threw trash and vandalized police cars before 80 Compton officers, assisted by 50 sheriff’s deputies, dispersed the crowd, Compton Police Capt. Steven Roller said.

Twelve people--all but one of them juveniles--were arrested, and there was an unconfirmed report of one injury.

In response to the widespread student walkouts, the LAPD went on a tactical alert at 11 a.m. Wednesday, allowing commanders greater flexibility in keeping officers on duty beyond their shifts and redeploying police to areas where needed.

In Santa Clarita, a march by more than 200 William S. Hart High and Placerita Junior High students was met with scorn by some residents as they watched the mostly Latino group chant Spanish slogans and carry Mexican flags. Many of the onlookers said they had planned to vote for Proposition 187 anyway, but the demonstration only strengthened their resolve.

“This is ridiculous to let a Mexican flag go down (the street),” Marylee Silvius, 67, said as she watched the students shouting as they passed a grocery store. “It just makes me angry. I don’t like protesters in the first place. I can feel for them, but illegal is illegal.”

“If they want our support, they should be waving an American flag,” said another shopper, who refused to give her name.

The Santa Clarita protesters did influence at least one person toward their way of thinking. Stacy Hobbs, 19, a community college student, said she had favored the proposition, but seeing the demonstration “makes me more sympathetic.”

“It really does, because they’re humans,” Hobbs said.

In South-Central Los Angeles, several hundred youngsters from Carver Middle School walked out in mid-morning and refused to board buses provided by school officials to return to campus. Police followed as the students broke into smaller groups and ran down side streets, finally fencing in most of the youngsters.

“This is what the suburban people who support this proposition don’t understand, that this is what’s going to happen if it passes,” said Alfred Rowe, heading home after watching the students finally leave on buses. “We already had one riot down here. We don’t need another.”

Meanwhile, both sides of the Prop osition 187 campaign began throwing their limited financial resources into advertising.

Taxpayers Against 187, a coalition of statewide organizations opposed to the measure, hit the airwaves in Los Angeles on Wednesday with its first TV ad. The 30-second spot is running on seven TV stations.

On the pro-187 side, two radio ad campaigns have started to supplement Gov. Pete Wilson’s TV ads that urge a “yes” vote. Also, the Federation for American Immigration Reform, a Washington lobbying group, has begun running radio spots statewide charging that special interest groups are seeking to defeat the measure.

In another development, U. S. Labor Secretary Robert Reich attacked the measure as “the wrong remedy.” He said illegal immigration could be halted more effectively by going after employers who hire undocumented workers.

Contributing to this story were Times staff writers Aaron Curtiss, Julio Moran, Jon D. Markman, Yvette Cabrera, Tina Daunt, Paul Feldman, John Glionna, Greg Hernandez, Jean Merl, Patrick J. McDonnell, Mimi Ko, Richard C. Paddock and Timothy Williams, and correspondents Eric Slater, Mark Sabbatini, Maki Becker, Leslie Berestein, Jon Garcia, Mary Moore, Psyche Pascual and Simon Romero.

* RAIN ON THEIR PARADE: About 24 protesting Birmingham High students get wet. B1