Ten more states sued the federal government on Friday over a directive to public schools on bathroom use by transgender students, adding their objections to those of 11 states that brought a lawsuit soon after the directive was released in May.

The latest lawsuit, which was filed in federal court in Nebraska, says that federal agencies like the Justice Department and the Education Department overstepped their authority with the directive, which requires schools to allow students to use the bathrooms that match their gender identity.

The government, the lawsuit said, essentially redefined the word “sex” in federal codes to include gender identity and undermined school districts’ authority.

“If you look at the history of Title IX, Congress never interpreted ‘sex’ to be so broadly defined,” Douglas Peterson, Nebraska’s attorney general, said in an interview.