WSIU's Jennifer Fuller contributed reporting to this story.
The Federal Bureau of Investigation and police at Southern Illinois University-Carbondale are investigating after someone mailed a threat to the university last night.
The threat prompted an safety alert to students, faculty and staff, but SIU-C spokesman Rod Sievers called that a precaution.
"The credibility of this threat is in doubt, the authorities are actively pursuing their investigation," Sievers said. "And if anything else is determined to warrant further action, certainly that would be relayed to the campus community."
The FBI would not release any additional information about the threat, including its nature or the targets.