The American Civil Liberties Union has told officials at a Nebraska school district they are violating students' First Amendment rights by allowing prayer at high school graduations.

Officials with Lakeview Community Schools in Columbus, Neb., were told to stop holding a high school graduation ceremony that subjects students to "unconstitutional religious messages," according to an ACLU press release.

The ACLU said district materials show the ceremonies carry an overwhelming message that the prayers are endorsed by the school district.

Superintendent Russ Freeman responded to the ACLU, saying parents run the ceremonies. He said he doesn't believe the district has done nothing wrong.