Two separate hand-scrawled messages were found Saturday in women's washrooms by students, the Chicago Tribune reported.

One said "The VA tech shooters messed up w/ having only one shooter." Another message mentioned Monday's date and said "things will change most hastily" at NIU.

The threats included a racial slur.

NIU President John Peters canceled exams Monday.

"We will not tolerate threats against individuals or groups," Peters said in a statement. "Nor will we tolerate hate speech of any type on this campus."

The school issued an advisory to staff and students, citing the security concern along with freezing rain as a reason for rescheduling exams.

"Only essential service personnel should report to work on Monday," the advisory said.

On April 16, Virginia Tech student Seung-Hui Cho shot and killed 32 people before taking his own life.