The usual tension of midterm exams at the University of Wisconsin-River Falls was heightened by an anonymous threat of campus violence on Wednesday.

"Beware the Ides of October, the time is nigh and the bullets will fly," warned the threat sent to the university in September. Every month has an ides — the midpoint on the old Roman calendar — and in October it falls on Wednesday the 15th.

The threat shadowed an otherwise gorgeous fall school day. Police heightened their presence on campus and faculty members had the option of adjusting their schedules, holding classes online or excusing student absences.

"We don't want to set the precedent of canceling classes every time someone makes an anonymous threat," said university spokesman Blake Fry, whose office handled a number of calls from worried parents throughout the day.

For the most part, classes and campus activities were unaffected by the increased security alert. But at a Wednesday job fair, Fry said, a third of the invited employers canceled because of the threat.

The last time River Falls faced a scare like this was five years ago, when racist graffiti scrawled in a library restroom threatened violence against minorities. Students responded by staging rallies to protest bigotry.

"The safety and security of the UW-River Falls campus community is our highest priority," University Police Chief Karl Fleury said in a statement. "There will be an increased law enforcement presence on or around campus for your overall safety. The UW-River Falls Police Department and its law enforcement partners continue to investigate this matter."

Police are asking anyone with information about the threats to contact them at 1-715-425-3133. Anyone who spots "any suspicious or unusual behavior or activity" around campus is asked to call 911 immediately.

Jennifer Brooks • 612-673-4008