Following the match, Mejbri took to Instagram to share his thoughts on the alleged incident, making it clear that he would not remain silent.
He wrote: "I will not be silent about what happened today. I will always call out racism whenever I hear or see it. That is the only way we change as a sport and a society. I am a strong person but nobody should have to experience this disgusting abuse on the pitch."
Burnley FC quickly addressed the situation and expressed their full support for Mejbri.
"Burnley Football Club is aware of an alleged comment made to Hannibal by Milutin Osmajic during our game against Preston North End which was reported to officials both during and after the game," a statement read.
"During the second-half Hannibal made referee Andrew Kitchen aware of the comment who has registered the complaint. The Club would like to thank the officials for their professional handling of the incident. The Club will continue to show its complete support to Hannibal and there will be no further comment made until the investigation has been completed."
Burnley manager Scott Parker addressed the situation after the game, acknowledging Mejbri’s distress and expressing sympathy for his player.
Speaking to BBC Sport, he said: "He's hurt. I think everyone could see that at the time, Hannibal's an emotional player and he was visibly very stressed by what was said. I don't want to get into the real details of what was said, I'm sure it'll come out in due course. Hannibal's reported it and is bitterly gutted really so we'll see what happens in the coming days."