CHATTANOOGA, Tenn. (AP) -- University of Tennessee-Chattanooga officials have stepped up an investigation into a string of bomb threats that disrupted the campus.
The Chattanooga Times Free Press reported students were taking makeup final course exams on Saturday, when they had expected to be headed home for the holiday break.
University Police Chief Robert Ratchford said the five threats this year are a plague when compared to one or two in most years.
Investigators released a photo of a person of interest on Friday and have put several campus buildings under around-the-clock surveillance.
Response to a single bomb threat can cost $100,000 in use of police, fire and university resources.
Ratchford said federal agencies have been called into the investigation.