ATLANTA (AP) — Civil rights icon and U.S. Rep. John Lewis has been hospitalized for undisclosed reasons.

Citing a statement from Lewis’ office, WSB-TV reports that the 78-year-old Georgia congressman was “resting comfortably” in a hospital Saturday night for “routine observation.”

READ MORE: Shooting And Flipped Vehicle Results In Section Of LBJ Freeway In Balch Springs Shut Down For Hours

The statement says Lewis expects to be released Sunday.

READ MORE: Suspect Charged In Connection With Gas Explosion At Dallas Apartment Complex

Lewis, a Democrat, played a key role in the civil rights movement and marched with the Rev. Martin Luther King Jr. in 1965 in Selma, Alabama.

Lewis was expected at an Atlanta event Saturday evening but did not attend.

MORE NEWS: Amid Fight Over Redistricting, Texas Legislature's 3rd Special Session Ends With Passage Of Bipartisan Bills

(© Copyright 2018 The Associated Press. All Rights Reserved. This material may not be published, broadcast, rewritten or redistributed.)