ACLU Nebraska says three counties accused of discriminating against immigrants seeking marriage licenses have until the end of June to change their practices -- or face a lawsuit.

The group sent final warning letters Thursday to Lincoln, Phelps and Platte counties. In April, the state American Civil Liberties Union alleged five counties were discriminating against legal immigrants. The group said it had investigated several reports of county workers turning away Spanish speakers.

ACLU Nebraska legal director Amy Miller said Hall County has made changes to ensure its procedures are fair. She also said Dawson County officials have said they are reviewing their policies.

Under state law, applicants for marriage licenses must show identification verifying their name and date of birth.