Two students at a Southern California high school will face "severe consequences" after a photo of them holding up a racist "promposal" sign sparked outrage among students, former students and parents on social media.

Palos Verdes High School Principal Dr. Allan Tyner said in a statement Wednesday that he would be "meeting with all students, class by class" to "review appropriate behavior and how the use of hurtful racial slurs like the one used on this recent picture posted on social media is unacceptable."

The photo, which was shared by several outraged Instagram and Twitter users Tuesday, shows the two teens holding up a sign with one of the student's names, followed by "you are racist but I would give anything for you to go with me to prom." Certain letters in the name and the sentence were capitalized and bolded to spell out the N-word.

A photo posted on social media shows two Palos Verdes High School student holding a promposal sign with a racial slur. via Twitter

"We have been in touch with the identified students and their families to inform them that we are forming a response and anticipate severe consequences," Tyner said in an email sent to parents Tuesday evening that was obtained by NBC News. In the same email, he described the word as "a slang term for African-Americans."

"I am heartened by the immediate response by our students and families on social media that make it very clear that our community does not support this behavior," Tyner added.

He said that school officials were investigating who took the photo, and if anyone else was present when the photo was taken. NBC News has blurred out the faces of the students and the letters spelling out the slur.

It's unclear who originally posted the photo online. Ava McCoy, 14, who is a freshman at Palos Verdes High School, told NBC News that neither of the students who were in the photo posted it to any of their social media accounts.

"I find the sign highly offensive and extremely hurtful being a person of color," McCoy said. "I think this behavior is intolerable and students need to be educated on the subject."

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The Palos Verdes Police Department said in a tweet that the department would have an increased presence at area schools Wednesday "due to recent social media postings."

Palos Verdes High School's prom is scheduled for Saturday. The theme is "Wish upon a star."

About 2 percent of the residents of the city in Los Angeles County are black, according to the most recent census data.

This isn't the first instance of students sharing photos of racial prom proposal signs on social media. Last year, a student in Florida posted a photo of him holding a sign that said "If I were black I’d be picking cotton, but I’m white so I’m picking you 4 prom?”

Photos of students in Ohio, New York and Texas holding up similar signs have made headlines this year.