According to reports, the US Department of Homeland Security set up a fake university in Detroit, Michigan, to target people that helped immigrants obtain jobs under a CPT student visa program that gives students permission to legally work in the US.

Eight people were taken into custody and charged with conspiracy to commit visa fraud and ‘harboring aliens for profit,’ reported Matthew Schneider, a U.S. Attorney for the Eastern District of Michigan.

The fake university dubbed the University of Farmington has been operating since 2015. The school had no classes, curriculum or faculty, but it had a website that gave the impression it was a legitimate university.

It was reported that the suspects helped more than 600 immigrants to illegally live and work in the US and actively harbored them to enroll the fraudulent university as part of ‘pay to stay’ scheme.

The students enrolled to obtain jobs under a student visa program called Curricular Practical Training, according to the paper. An indictment unsealed Wednesday said the defendants helped 600 undocumented immigrants to enroll in the fake university in exchange for cash, kickbacks and tuition credits.

“We are all aware that international students can be a valuable asset to our country, but as this case shows, the well-intended international student visa program can also be exploited and abused,” Schneider said in a statement.

The indictment alleged the students who enrolled “knew that they would not attend any actual classes, earn credits or make academic progress towards an actual degree,” but enrolled only to remain in the country. Student visas allow individuals to remain in the U.S. if they are enrolled in school and working toward a degree. If not, they must leave within 60 days.