SAN DIEGO -- Immigrant rights advocates Friday urged San Diegans to join a nationwide boycott on Monday, while other activists said immigrants should participate in their rally -- after going to school or work.

Thousands of San Diego-area protesters are expected to join in what is being billed as the "Great American Boycott" to show what America would be like without illegal immigrants.

Rallies -- heavily publicized by DJs on Spanish-speaking radio stations -- are planned throughout San Diego County and the nation.

At 1 p.m. Monday, participants will march from San Ysidro Community Park to the international line and back again, joined by a contingent from Mexico.

The event will feature speakers, voter registration, cultural presentations and musical performances, all emphasizing a call for "full rights" for undocumented immigrants, planners said.

Meantime, "Day of Action" demonstrations are scheduled for 5:30 p.m. in San Diego's Balboa Park and Grape Day Park in Escondido.

The rallies -- set for the evening hours so as not to interfere with work or school -- also will feature speeches, political activism and live music, along with candlelight vigils.

Law enforcement and school officials throughout the Southland have urged students to stay in school Monday and participate only in late-afternoon demonstrations.

The San Diego Police Department will deploy extra officers to monitor the rallies, according to SDPD public information Officer Gary Hassen.

The sheriff's department was still finalizing its enforcement plans for Monday's expected protests, Lt. James Bolwerk said.

Earlier this week, the superintendents of San Diego Unified School District and Sweetwater Union High School District held news conferences urging students to find ways to express their views without skipping classes.