SAN FRANCISCO — Jose Luis Sanchez was a veteran cook at El Balazo, working at the popular Bay Area taqueria chain for eight years before a Friday immigration raid ended his career and left his family's future uncertain.

"My kids are sad," said the 32-year-old San Pablo resident, one of 63 illegal immigrants employed by the 11-restaurant chain who were arrested Friday by U.S. Immigration and Customs Enforcement. "They want to know if they're going to send me to Mexico."

With an electronic surveillance bracelet attached indefinitely to his ankle, Sanchez contemplated his future Monday afternoon outside the Sansome Street high-rise building that is home to the Immigration and Customs Enforcement's Office of Detention and Removal Operations. As he spoke, a few hundred people marched up and down the sidewalk, protesting last week's raids on the restaurants.

"A lot of our municipalities are feeling these are improper invasions," said state Sen. Carole Migden, D-San Francisco, who joined the Monday afternoon protest. She said that the raids violate San Francisco's desire to be a "safe haven community" for undocumented immigrants.

Advocates said the raids affected families throughout the Bay Area. The Rev. William McGarvey, pastor of the Community Presbyterian Church in Pittsburg, said he was worried that the raids would send families "further underground," eroding their relationships with local institutions.

Sanchez, who hails from Guadalajara, Mexico, said he was having an ordinary morning Friday when two men and a woman he later assumed were plainclothes agents showed up at the restaurant where he works just off Highway 101 in San Francisco.

"The first one ordered chorizo and eggs," Sanchez said. "The next one ordered a burrito with carne asada. The woman ordered a burrito with beans."

But then the woman, he said, asked for a bathroom key and disappeared. Soon after, Sanchez said, the restaurant was stormed by uniformed agents who closed off the establishment and began questioning all the workers inside.

By late Friday, all but 10 of the 63 El Balazo workers arrested earlier in the day had been allowed to go home to await future immigration hearings, said Immigration and Customs Enforcement spokeswoman Virginia Kice.

"Some were released on their own recognizance; others will be subject to electronic monitoring," she said.

On Monday afternoon, nine immigrants, all male, remained in custody. Of those, one is a suspected gang member, one was previously deported, and three are juveniles thought to be in the country without parental supervision, Kice said. The remaining four "were offered an opportunity to be released but refused to cooperate with the electronic monitoring," Kice said.

The juveniles include two 17-year-olds and a 15-year-old, who have been turned over to the U.S. Department of Health and Human Services, Kice said. No criminal charges have been filed, though the investigation into operations at the 11 El Balazo restaurants continues, Kice said.

"Our official statement is that the investigation is ongoing, and we will go where the evidence leads us," she said.

The chain's founding owner, Marino Sandoval, a Pleasanton resident, could not be reached for comment Monday. Many of his restaurants reopened over the weekend, while others remained closed after the raids.

Sandoval, who was born in Mexico, moved to Alameda with his family when he was a toddler. After working in his brother-in-law's San Francisco sandwich shop, he opened his first deli, which he called the Golden Gate Flyer, in 1976 in the Financial District, using money from the sale of his first house. In 1981, he sold the business to his brother and began working for Sysco food corporation.

Twelve years later, he opened the first El Balazo on Haight Street in San Francisco. In a 2005 interview with the Times, Sandoval said that the name El Balazo, which means "the gunshot" in Spanish, had been aimed to impart speedy food service. El Balazo instantly gained a reputation for its authentic flavors and fast delivery.

Sandoval, who had moved to Danville with his wife, Nicole, in 1988, leveraged the restaurant's popularity to expand to the East Bay suburbs, opening Nicole's Diner in 1995 in San Ramon. The following year, Sandoval opened a second El Balazo on Market Street in San Ramon. That was followed by El Balazo openings in 1998 in Danville and in 1999 in Pleasanton. In 2005, the couple opened a second El Balazo in Pleasanton.

All of the El Balazo restaurants operate out of leased space.

In March 2007, Internal Revenue Service agents served search warrants at several El Balazo restaurants. Because the affidavits were sealed, the IRS would not disclose the reason for the searches.

Staff writer Sophia Kazmi contributed to this story. Reach Matt O'Brien at mattobrien@bayareanewsgroup.com.