Commencement is generally a time of happiness, but for some African-American graduates at the University of Florida in Gainesville, their celebration during the ceremony led to being manhandled by a school official.

The students said they were “strolling,” a tradition common among Black fraternities, when they received their degrees Saturday before a graduation marshal forced them off the stage, TIME reports.

Videos showing the students being yanked off the stage went viral online, with many people calling out the school.

Kent Fuchs, president of the University of Florida, apologized for the incident on Twitter and said he would contact each student involved.

“During one of this weekend’s commencement ceremonies, we were inappropriately aggressive in rushing students across the stage,” he wrote. “I personally apologize, and am reaching out to the students involved.”

Oliver Telusma, 21, told the Gainesville Sun that he was embarrassed when the usher grabbed him under his arm.

“I had just started … and he picked me up and turned me around, which I thought was kind of embarrassing and degrading to be handled in that manner,” Telusma said. “It was just really uncalled for, especially for anyone not martially trained to do that.”

On Sunday, Fuchs said that students don’t have to be worried about it happening during future ceremonies as the “practice has been halted.”