A school board in Alaska has removed a collection of classic novels from classrooms over "controversial" themes like language and sexual references.

The Mat-Su Borough School District, north of Anchorage, took some of the world's best known authors and novels off the approved list of works teachers could use for instructing students. According to members of the school board, which voted 5-2 to remove the books, if they were read in a corporate office environment today, they would be dragged into an equal opportunity complaint.

The list of works, authors and the reasons for removal include:

The Great Gatsby, by F Scott Fitzgerald for "language and sexual references".

Invisible Man, by Ralph Ellison for "language, rape and incest".

I Know Why the Caged Bird Sings, by Maya Angelou for "sexually explicit material, such as the sexual abuse the author suffered as a child, and its 'antiwhite messaging'".

Catch-22 by Joseph Heller for "a handful of racial slurs, the characters speak with typical 'military men' misogyny and racist attitudes of the time. There are scenes of violence both hand to hand and with guns, and violence against women."

The Things They Carried by Tim O'Brien for "profanity and sexual references".

School board vice president Jim Hart told NBC News on Tuesday the content could potentially harm students.

"If I were to read these in a corporate environment, in an office environment, I would be dragged into EO," an equal opportunity complaint proceeding, Mr Hart said. "The question is why this is acceptable in one environment and not another."

Dianne K Shibe, president of the Mat-Su Education Association teachers union, said parents and her members were stunned.