In the 1990s, the U.S. used Guantánamo Bay to hold Haitian and Cuban immigrants intercepted at sea. The Trump administration is now sending to Guantánamo people who were arrested on U.S. soil. That hasn’t happened before.

Immigrant rights groups sued the Trump administration on Saturday in hopes of stopping the transfer of migrants from the U.S. to Guantanamo Bay.

The American Civil Liberties Union, which filed the lawsuit in federal court in Washington, D.C., said the transfers violate U.S. immigration law by moving the detainees outside of the country and aim to stoke fear without a legitimate rationale.