Four Mexican nationals operating out of Cobb County were sentenced to prison Wednesday for making and selling counterfeit documents used by illegal immigrants to avoid detection in the United States, federal authorities said.

“These defendants ran an operation that enabled many illegal aliens to get their hands on identification that made it appear as if they were legally in the United States,” U.S. Attorney Sally Quillian Yates said in a news release.

“This crime creates impacts our community in many ways, not the least of which is the negative impact on the credit history and financial well-being of people whose Social Security numbers were unlawfully used on the counterfeit documents,” Yates said. “I encourage everyone to regularly check their credit report for unusual activity.”

U.S. District Judge Steve C. Jones handed down the sentences in federal court in Atlanta.

Sentenced on the charge of conspiring to produce fraudulent identification documents were Ruben Osorno Altamirano, 31; Jose Luis Israel Legoretta Castillo, 31; Juana Hernandez Fonseca, 40; and Jose Molina Vasquez, 33, prosecutors said. All previously pleaded guilty.

Four additional defendants also have pleaded guilty and are awaiting sentencing.

The operation was brought to the attention of Homeland Security by the Metro Cobb Smyrna Task Force in January 2010. The ring worked out of a coin laundry in Smyrna, offering its services to illegal immigrants who used the facility. Prosecutors described how the case was investigated:

Between March 2010 and August 2011, undercover investigators with Homeland Security, the U.S. Secret Service and the Governor’s Office of Consumer Protection bought counterfeit  Social Security cards, permanent resident cards and Georgia driver’s licenses at various locations in Cobb County.

Agents determined where the documents were being produced and, on Sept. 8 of last year, executed a search warrant at an apartment complex in Marietta.

Investigators seized document-making equipment including computers, printers and electronic files containing more than 2,000 images of fraudulent IDs – Social Security and permanent resident cards, birth certificates and driver’s licenses from more than 20 states, and firearms.

Altamirano’s prison sentence was 28 months in prison, while Castillo and Vasquez each were sentenced to 10 months and Fonseca got nine months, prosecutors said. Each defendant also was sentenced to two years of supervised release.

Awaiting sentencing during the next three months are Tiburcio Martinez Santos, 21, Isidoro Espinoza Araujo, 44, Mauricio Jonathan Espinoza Hernandez, 20, and Edgar Marquez Salazar, 37, all of Mexico, prosecutors said.

Assistant U.S. Attorney Jeffrey A. Brown prosecuted the case.