A student protest at the University of Mississippi against the re-election of President Obama turned disorderly on Wednesday morning, with some students chanting racial epithets and two arrested for disorderly conduct.

The university said in a statement that a crowd of 400 people formed at the student union shortly before midnight after reports of a riot spread on social media. Some students yelled racial slurs and profanity in anger over Mr. Obama’s re-election, the statement said. Photographs posted online showed students lighting Obama campaign signs on fire.

The university’s chancellor, Dan Jones, said, “All of us are ashamed of the few students who have negatively affected the reputations of each of us and of our university.” No one was injured, and no property was damaged, but Dr. Jones said the campus police were investigating.

Mr. Obama lost to Mitt Romney in Mississippi by a wide margin. But after Mr. Obama was declared the winner in the national race, 30 or 40 people began protesting on the campus, and a rumor spread through Twitter that it was a riot. “The gathering seems to have been fueled by social media, and the conversation should have stayed there,” Dr. Jones said.