Eleven people in California have been indicted on charges of running a large-scale marriage fraud “agency” that arranged hundreds of sham marriages in order for undocumented immigrants to obtain green cards, the U.S. Attorney’s Office in Boston said Thursday.

The Los Angeles-based operation arranged phony marriages and submitted fraudulent immigration documents for at least 400 clients between October 2016 and March 2022, charging the newlywed clients between $20,000 to $30,000 in cash, according to the indictment.