Administrators at a California high school sent five students home on Wednesday after they refused to remove their American flag T-shirts and bandannas -- garments the school officials deemed "incendiary" on Cinco de Mayo.

The five teens were sitting at a table outside Live Oak High School in Morgan Hill, Calif., on Wednesday morning when Assistant Principal Miguel Rodriguez asked two of them to remove their American flag bandannas, one of their parents told FoxNews.com. The boys complied, but were asked to accompany Rodriguez to the principal's office.

The five students -- Daniel Galli, Austin Carvalho, Matt Dariano, Dominic Maciel and Clayton Howard -- were then told they must turn their T-shirts inside-out or be sent home, though it would not be considered a suspension. Rodriguez told the students he did not want any fights to break out between Mexican-American students celebrating their heritage and those wearing American flags.

Dariano's mother, Diana, told FoxNews.com she and parents of the other four students are now demanding an apology from officials and are considering a lawsuit.

"We want an apology," Diana Dariano said Thursday. "Who in the United States of America would have an issue with that? It's a sad, sad day."

Dariano said her son has at least four T-shirts with American flags that he wears often and did not try to cause any conflict at school.

"I'm more hurt than anything," she said. "It is so hurtful and disrespectful the way this has turned. These are American kids."

The boys told Rodriguez and Principal Nick Boden that turning their shirts inside-out was disrespectful, so their parents decided to take them home.

"I just couldn't believe it," Julie Fagerstrom, Maciel's mother, told the Morgan Hill Times. "I'm an open-minded parent, but it's got to be on both sides. It can't be five kids singled out."

Galli told NBC Bay Area, "They said we could wear it on any other day, but today is sensitive to Mexican-Americans because it's supposed to be their holiday so we were not allowed to wear it."

In a statement released Thursday, Morgan Hill Unified School District Superintendent Wesley Smith characterized the incident as "extremely unfortunate" and said the matter is under investigation.

"The Morgan Hill Unified School District does not prohibit nor do we discourage wearing patriotic clothing," Smith's statement read. "The incident on May 5 at Live Oak High School is extremely unfortunate. While campus safety is our primary concern and administrators made decisions yesterday in an attempt to ensure campus safety, students should not, and will not, be disciplined for wearing patriotic clothing. This matter is under investigation and appropriate action will be taken."

Officials at Live Oak High School did not return several messages seeking comment on Thursday. A secretary told the Morgan Hill Times that Boden and Rodriguez were unavailable for comment on Wednesday.

According to its website, Live Oak High School is a 1,300-student institution in the southern part of Santa Clara County, with most students residing in the nearby cities of Morgan Hill and San Jose.

"The student population reflects the rich ethnic and socioeconomic diversity of the community," the website reads.

More than 100 students were spotted wearing the colors of the Mexican flag -- red, white and green -- as they left school, including some who had the flag painted on their faces or arms, the Morgan Hill times reported.

While bandannas of any color are banned at the school, its dress code policy does not contain references to American flags.

"However, any clothing or decoration which detracts from the learning environment is prohibited," the policy reads. "The school has the right to request that any student dressing inappropriately for school will change into other clothes, be sent home to change, and/or be subject to disciplinary action."

Freshman Laura Ponce, who had a Mexican flag painted on her face and chest, told the Morgan Hill Times that Cinco de Mayo is the "only day" Mexican-American students can show their national pride.

"There was a lot of drama going on today," Ponce told the newspaper.

Some other Mexican-American students reportedly said their flags were taken away or asked to be put away, but no other students were sent home on Wednesday.

Eugene Volokh, a professor of law at the University of California-Los Angeles, said the students are protected under California Education Code 48950, which prohibits schools from enforcing a rule subjecting a high school student to disciplinary sanctions solely on the basis of conduct, that when engaged outside of campus, is protected by the First Amendment.

If the school could point to previous incidents sparked by students who wore garments with American flags, they could argue that the flag is likely to lead to "substantial disruption," Volokh said.

"If, for example, there had been fights over similar things at past events, if there had been specific threats made," he said. "But if [school officials] just say, 'Well, we think it might be offensive to people,' that's generally speaking not enough."

Volokh said the students and their parents likely have a winning case on their hands if they decide to take the matter to court.

"Oh yes, it's almost open and shut," he said.

Lis Wiehl, a former federal prosecutor and a Fox News legal analyst, said the incident appears to a "blatant" violation of the students' First Amendment right to free speech. She noted that inciting violence is an exception to a First Amendment legal defense, but Wiehl said she saw no indications that the students provoked anyone.

"Unless I'm missing something, this seems like a blatant violation of the First Amendment," said Wiehl, adding that uniforms are not required at the public school. "And they're wearing, of all horrific things, the American flag."