Western Illinois University remains on high alert after it received another bomb threat Thursday night.
"I've been here 17 years and we've never had a succession of threats like this before," Director of University Relations, Darcie Shinberger said .
Thursday's threat marked the sixth bomb alert WIU has received in the last two weeks. Not all of the threats have been deemed credible by the university. At least one has been categorized as a hoax, officials said.
Complicating the investigation is the possibility that the six threats are unrelated, officials said. The first three in November were all phone calls while the last two have been notes.
"We believe it's probably a different person leaving the notes," said Shinberger. "The language used in the phone calls and the language used in the notes is inconsistent, but the investigation is still ongoing."
The Macomb, Illinois-based university has increased to $10,000 the reward for any information leading to an arrest in the spate of scares.
Following is a chronology of events at Western Illinois University: