A South African school is under fire for allegedly separating students by race. A video posted on social media Wednesday purports to show teachers from Curro Roodeplaat private school in Pretoria racially segregating children off of buses as they prepare for a field trip.

The video, which went viral on Facebook, appears to show black students and white students exiting from separate buses as they arrive at a school camp. The teachers then lead the two groups of school children in separate lines in opposite directions.

Curro Roodeplaat released a statement Thursday denying any racial segregation. The school said its students were separated by school classes so that children taught in English rode in one bus while those taught in Afrikaans rode in another. English classes are comprised mostly of black children while Afrikaans classes are attended by a majority of white children, the statement said.

“The children were in the buses according to class. We are a dual-medium school and parents have made a choice as to whether their children be taught in Afrikaans or English. The Afrikaans children were in one bus and the English in the other,” the school said in the statement obtained by Eyewitness News in Johannesburg. “A video taken of this outing showed the various groups of learners. And with no explanation people assumed that the groupings were organized according to race.”

Last month, the same school was found guilty of racial segregation after claims surfaced of young children being assigned to classes according to their race. Curro Roodeplaat said then that they grouped the school children based on language and culture as well. The Gauteng Department of Education launched an investigation and released a damning report. The Pretoria-based school accepted the findings and admitted to being pressured by white parents to separate black and white students.

“There was indeed segregation of learners at the school and this was confirmed by Curro management,” Gauteng Education MEC Panyaza Lesufi told Eyewitness News in Johannesburg. “This is completely unacceptable; it’s discriminatory and contrary to the provisions of section nine of our constitution.”