CAMPO, Calif.—Volunteers patrolled remote mountains outside San Diego for human traffickers and drug smugglers Saturday, launching a campaign modeled after an effort in the Arizona desert to draw attention to the nation’s porous border with Mexico.

Jim Chase, a former Arizona Minuteman volunteer who cut ties with that group’s leadership, is leading California Border Watch, which mobilized Saturday to patrol a 26-mile rural stretch of rolling hills from Jacumba to Tecate through Aug. 7.

Chase, a retired postal worker from Oceanside, said he and others will carry guns for self-defense but will not initiate attacks.

“The guns are for one reason—to keep my people alive,” he said in an interview Friday.

About 30 volunteers came out Saturday to join the patrol, Chase said. A loud group of protesters, however, outnumbered the volunteers and Chase temporarily drove away from the border in the afternoon to chants of “racists go home.”

Earlier this week, the Web site for Chase’s group urged volunteers to bring baseball bats, mace, pepper spray and machetes. Chase said he removed those items after the U.S. Border Patrol expressed concern.

The group has set up headquarters outside the Veterans of Foreign Wars post in Campo, an unincorporated mountain village of about 1,200 people located about a mile north of the Mexican border and 40 miles east of San Diego.

A group of about 100 migrant activists staged a rally Saturday against the volunteer patrol, said Stan Isham, a supervisory border patrol agent. The rally was civil and no problems were reported, Isham said.

Rich Macgurn, a human rights activist with Gente Unida (People United), said the number of patrol volunteers was “pretty scarce” and that protesters had only spotted a few of them.

The Border Patrol was setting up a command post outside its Campo station, and San Diego Sheriff Bill Kolender said deputies would closely monitor the area.

“We will not tolerate any kind of hate crimes, we will not tolerate any violations of the law, and we will see to it that the Border Patrol is able to do their job in a safe manner,” Kolender said.

Chase said he expected 100 and 200 volunteers would join the patrol throughout the three-week vigil.

Volunteers will call the Border Patrol if they spot illegal border crossers, Chase said. He won’t chase illegal immigrants but said others might.

“If somebody’s stupid enough to do it, I’m not going to stop them,” he said.

Chase, who turned 58 Saturday, has been feuding with other activists organizing civilian patrols in an effort to turn public attention to illegal immigration. The campaigns are modeled after patrols in Arizona that garnered international attention and criticism on both sides of the border in April.

Chase has traded harsh words with Andy Ramirez, whose Chino-based Friends of the Border Patrol plans a civilian patrol in San Diego County in September. He also cut ties with Minuteman co-founder Chris Simcox of Arizona, who hopes to organize a patrol along the southern U.S. border in October.