Several protesters were arrested Monday at the Iowa state Capitol, where shouts of “trans rights are human rights” reverberated throughout the building as Republican lawmakers advanced a bill that would strip the state civil rights code of protections based on gender identity.

Hundreds gathered inside the Iowa State Capitol to protest against a bill that would eliminate civil rights protections against trans people.

If the bill is signed into law, Iowa would become the first U.S. state to roll back protections for a recognized class under its civil rights statutes.