A girl detained in a raid of a group of suspected illegal immigrants in Maricopa County, Ariz., last week is a 5-year-old who left El Salvador to try to reach relatives in California, NBC News has learned.

The girl was traveling with strangers as part of a smuggling group, according to the Maricopa County Sheriff’s Office. Agents say none of the 15 adults caught with her in a van knew who she was, or where her parents might be. 

The group was arrested Friday night at an undisclosed location in northern Maricopa County.

"It was part of a human-smuggling investigation that we've been investigating throughout the Valley," sheriff’s spokesman Chris Hegstrom told azcentral.com.

The girl was turned over to U.S. Immigration and Customs Enforcement, which said it transferred her to the custody of the U.S. Department of Health and Human Service’s Office of Refugee Resettlement.

The girl's first name is Rosa and she is now in the care of a faith-based social-service organization, Health and Human Services sources told NBC News on Thursday. 

Most of the other suspected illegal immigrants, who claimed to be from Mexico, were booked into jail, the Sheriff’s Office said. They were on their way to destinations in to New York, New Jersey, Kansas, Texas, California, Connecticut and Kentucky and told authorities they paid between $300 and $3,500 to be smuggled across the border, KPHO-TV reported.

"We enforce the human-smuggling laws here," said Sheriff Joe Arpaio, the no-nonsense lawman known for his get-tough efforts to combat illegal immigration. "Every chance I can get to take action on my own without turning them over to ICE, I do. Especially with the new policy the president has," he was quoted as saying by azcentral.com.

Three men in the arrested group were turned over to ICE and deported to Mexico, ICE officials in Arizona said.

It’s not uncommon for unaccompanied children to be found among groups of illegal aliens crossing the Arizona border from Mexico.

ICE officials in Phoenix said they referred have referred more than 1,600 unaccompanied alien juveniles to Health and Human Services this fiscal year for placement in juvenile shelters.

The arrests announced by Arpaio’s office came after President Barack Obama introduced a policy that halts the deportation of some young people brought to the United States illegally by their parents.

Under the new guidelines, illegal immigrants younger than age 30 can apply to stay provided they were younger than 16 when they arrived in the U.S., have lived here for at least five years and have no criminal record. They also must be students, a high-school graduate, have a GED diploma or have been honorably discharged from the military or Coast Guard.

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