I had the unfortunate experience of dealing with a racist security guard at Belgrade Nikola Tesla Airport. The guard was unprofessional and rude, and treated me with contempt and disrespect. He asked me intrusive questions about my ethnicity and seemed to think I was a threat simply because of the color of my skin. His behavior was unacceptable. I tried to get someone else to help me but no one did. I couldn't even file a complaint. I would not recommend flying through Belgrade Nikola Tesla Airport if you can avoid it due to the discrimination from security personnel.