CEDAR RAPIDS (AP) - U.S. attorneys officials say four men have been charged with failing to register as a sex offender.

The federal indictments against the men were filed this week in U.S. District Court in Cedar Rapids. Officials say the cases are unrelated.

They involve Marvino Crawford, 31, of Cedar Rapids; Keith Taylor, 45, of Waterloo; Jody Schafer, 33, of Cedar Rapids; and Jon Schrandt, 28, of Cedar Falls.

Officials say Schrandt appeared in court for an arraignment on Wednesday and was released. His trial was scheduled for Sept. 22.

The other men were being held in state custody and they had not yet been arraigned.