Miami-Dade County is facing a federal lawsuit over its decision to detain immigrants after President Donald Trump said he would defund “sanctuary cities.”

The University of Miami School of Law's Immigration Clinic filed the lawsuit Wednesday, challenging as unconstitutional the policy of keeping immigrants in jail to collaborate with federal law enforcement. Miami law firm Kurzban, Kurzban, Weinger, Tetzeli & Pratt and the American Civil Liberties Union of Florida are also on the case.

The plaintiff, 18-year-old Garland Creedle, claims he paid his bond after being arrested over an alleged domestic dispute. But instead of releasing him, the county jail held him for immigration officials, even though he is a U.S. citizen by birth, according to the lawsuit.