Two Long Island high school students have been suspended indefinitely for allegedly bringing a Confederate flag to a sporting event.

Brother Gary Cregan, the principal at St. Anthony's High School in South Huntington, told WCBS-TV the boys walked into the after-hours sporting event with the flag draped around their shoulders.

"The African-American students who immediately saw it really exercised heroic restraint and fortunately a teacher immediately confiscated the flag and took the students out of the gym,” Cregan said.

The two seniors were initially suspended for 10 days, but Cregan decided Tuesday they won’t be allowed back, the station reported.

Cregan wrote a letter to their parents, telling them that the use of symbols “designed to revive past injustices or to inflame discrimination or racial intolerance, is completely unacceptable and profoundly offensive," Newsday reported.

“I find it just very hard to even imagine why any student in 2014 would even consider or think that a Confederate flag would be anything other than a symbol of hate,” Cregan told WCBS-TV.

While St. Anthony’s is a private Catholic school and generally not subject to First Amendment limitations, a New York Civil Liberties Union official said students be able to openly express their views, even those considered offensive.

“Our motto is more speech, not censorship or punishment,” NYCLU director Donna Lieberman told Brown told the station. “Helping children understand the impact of this patently offensive expressive activity.”

Cregan said there are limits to students' free speech rights.

“I certainly think this particular symbol of hate falls in the category of something that should be excised from our culture,” he said.

The students involved did not respond to WCBS-TV's requests for comment.

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