A boarding school in England came under fire after an image of student dressed in blackface on its campus surfaced online. Pictured is a classroom on Oct. 30, 2014 in Paris, France. Stephane De Sakutin/AFP/Getty Images)

A boarding school in South East England has issued an apology after a photo of students dressed in blackface on its campus circulated on social media Thursday.

Three high school seniors at the Oratory School in Oxfordshire showed up to a photo shoot in black makeup while two other pupils at the school dressed as slave owners holding what appeared to be guns.

Headmaster Joseph Smith had prevented the costumed students from taking part in an official school photo. The students, however, took their own picture, which ended up on Instagram with the caption, "Revolt."

When asked, the teens said that their black friends weren’t bothered by the idea and had joined them dressed as slave owners, according to the Reading Chronicle.

The incident sparked outrage as some took to Twitter and condemned the boys' actions.

"It's 2018 and not much has changed! Not only did @oratoryschool allow students to do blackface. They have completely ignored the issue and have yet to apologize. I guess racism is excused at this school," one user wrote.

"Pupils at Oratory School decided to paint themselves black and pretend to be slaves for an Instagram photo and people are defending their actions as "banter,” is it banter if I punch you in the face for being stupid?" another wrote.

The Roman Catholic school issued a statement that the "pupils involved have been punished as part of our disciplinary process."

"The headmaster refused to allow the offensively-dressed pupils to participate, and the photo was taken without them being included. The photo - the existence of which we were unaware - that was taken and posted on social media was taken unofficially and was in no way with the consent or blessing of the school," a school spokesman said according to BBC News.

"We are extremely shocked and saddened that this has happened and apologize unreservedly for the offense caused. We are dealing with this internally," the statement continued. "We will strengthen our tutorial program to ensure that it is understood by all our pupils that such representations are utterly unacceptable."

The school, which has tuition fees of over £11,000 ($13,165.77) each term said it allows soon-to-be graduates to take "formal leavers" photos as well as an "informal" photo in which the students get to dress up in costume.

It added that the school "unequivocally condemns racist imagery of any sort: we are a diverse and inclusive community."