A protest at the University of Mississippi against the re-election of President Barack Obama grew into crowd of about 400 people with shouted racial slurs as rumors of a riot spread on social media. Two people were arrested on minor charges.

The university said in a statement Wednesday that the gathering at the student union began late Tuesday night with about 30 to 40 students, but grew within 20 minutes as word spread. Some students chanted political slogans while others used derogatory racial statements and profanity, the statement said.

The incident comes just after the 50th anniversary of violent rioting that greeted the forced integration of Ole Miss with the enrollment of its first black student, James Meredith.

Ole Miss Chancellor Dan Jones promised an investigation and said “all of us are ashamed of the few students who have negatively affected the reputations of each of us and of our university.”

On Wednesday night, about 700 people held up candles and called for racial harmony outside the administrative building at the university in Oxford, countering Tuesday’s protest over Obama’s re-election.