Denver-based Chipotle Mexican Grill, Inc., revealed last week that it fired 450 Minnesota employees last year after an audit by the Department of Homeland Security.

The restaurant chain divulged the exact number of workers who were fired in its annual report, which was filed on February 17 with the U.S. Securities and Exchange Commission. The company previously confirmed that some local employees had been let go but did not disclose the number.

The company-which had about 1,200 employees in Minnesota-was required to fire the employees because the audit revealed they were illegal workers. At the time of the firings, Chipotle told the Star Tribune that workers were given opportunities to provide documents that could prove they were legally able to work in the United States.

Chipotle also said that similar audits are currently being conducted in Virginia and the District of Columbia.

In the report, the company said that the firings resulted “in a temporary increase in labor costs as we train new employees, as well as some degree of negative publicity.”

Following the firings, a group of workers filed a lawsuit against Chipotle claiming that the company did not comply with a Minnesota law requiring all back pay to be distributed within 24 hours of discharge.

Chipotle issued a statement earlier this month saying that claims made in the suit are without merit and that the company will defend itself vigorously.

“We have paid every employee everything that they were owed including wages, accrued vacation, and bonuses,” the company wrote. “We provided contact information to employees so anyone who did not feel they were paid everything they were owed could contact us, and we have heard from only a few employees.”