A National Mexican Restaurant Chain has been forced to fire hundreds of immigrant workers over the past few weeks following Immigration and Customs Enforcement (ICE) raids at its Minnesota restaurants. ICE had been conducting a probe that centered on worker employment eligibility at the company’s 50 restaurants here.

ICE had informed the chain several months ago that it was facing an I-9 audit (an inquiry to verify that workers can legally work in the U.S.) according to a company spokesman. ICE found “suspect documents” at 50 of the chain’s Minnesota restaurants, forcing the chain to fire employees. ICE also plans to check I-9 compliance with audits of the chain’s restaurants in Virginia and Washington, D.C.

A National Mexican Restaurant Chain spokesman said that the chain requires two different documents to verify the identity of all of its workers, but forged documents are commonly used by illegal immigrants.

A 35 year-old mother of four, who was working illegally at the chain, accused the chain of knowing beforehand that some workers didn’t have valid papers. She said that the chain fired her without warning after 6 years of employment with the chain. Other immigrants had as much as 10 years of employment with the chain, according to her.

The raids dampen the chain’s plans for expansion, creating disruption for the chain and its employees, according to a National Mexican Restaurant Chain spokesman. The chain had plans to open 145 restaurants this year. Stock gain has skyrocketed more than 500 percent over the last couple of years.

The Obama Administration has targeted 2740 companies for I-9 compliance in the fiscal year ending September 30th. It has fined businesses a record 7 million dollars for those who hired illegal workers.

Both legal and illegal immigrant workers accounted for 24 percent of all workers in the food service and restaurant industries between March, 2009 and March, 2010. National Mexican Restaurant Chain owns and operates nearly 1,100 restaurants and employs about 25,000 nationwide.