Updated at 5:15 a.m. ET Friday
The University of Mississippi says it has asked the FBI to investigate three students who posed with guns at a civil rights memorial that commemorates the 1955 killing of Emmett Till.
The Instagram photo, published by the Mississippi Center for Investigative Reporting, shows three white men posing near the marker at the Tallahatchie River, where Till's body was pulled from the water. One man is holding a rifle, and another an assault-style weapon, and the sign is pocked with bullet holes.
It was unclear if the bullet holes were made by the students or if they were remnants of previous vandalism, according to The New York Times.
Emmett Till was a 14-year-old black boy from Chicago visiting relatives in Mississippi when he was abducted and killed by two white men for allegedly whistling at a white woman in a case that drew national attention to lynchings in the South.
A University of Mississippi spokesman says campus police reported the image to the FBI which declined to investigate because the photo did not pose an immediate threat. The FBI office in Jackson declined to comment. Local media report the U.S. attorney has referred the matter to the U.S. Justice Department's Civil Rights Division.
The Ole Miss spokesman called the image offensive, but says it does not violate the school's code of conduct. The students have been suspended by their fraternity, the Kappa Alpha Order, an organization that glorifies the Confederate South.