The U.S. Department of Justice on Thursday sued Facebook alleging it discriminated against U.S. workers in hiring, favoring foreign workers on the H-1B visa, the agency announced Thursday.

At issue are 2,600 positions paying an average salary of about $156,000 that the Menlo Park social media giant allegedly set aside for foreign workers it wanted to sponsor for green cards, the Justice Department said in a news release.

“Rather than conducting a genuine search for qualified and available U.S. workers for permanent positions sought by these temporary visa holders, Facebook reserved the positions for temporary visa holders because of their immigration status,” the department said.

“Facebook sought to channel jobs to temporary visa holders at the expense of U.S. workers by failing to advertise those vacancies on its careers website, requiring applicants to apply by physical mail only, and refusing to consider any U.S. workers who applied for those positions.

“Facebook’s discriminatory recruitment and hiring practice is routine, ongoing, and widespread.”

A Facebook spokesperson said in an emailed statement that the firm has been cooperating with the department, but disputes the allegations.

The alleged discrimination occurred between January 2018 and Sept. 18, 2019, the department alleged.

The purported offenses occurred when visa holders requested permanent positions under the green card process, which triggers a legal requirement for employers to ensure that no U.S. workers were available, according to the lawsuit.

“Not only do Facebook’s alleged practices discriminate against U.S. workers, they have adverse consequences on temporary visa holders by creating an employment relationship that is not on equal terms,” the department alleged. “Such temporary visa holders often have limited job mobility and thus are likely to remain with their company until they can adjust status, which for some can be decades.”

The administrative lawsuit was filed by the department’s Civil Rights Division in the department’s Executive Office for Immigration Review. The division is seeking an order forcing Facebook to stop its alleged illegal practices and to pay “an appropriate civil penalty.”