Five community colleges in the Denver area were closed or locked down after threats were made against them.
Police later said the email threat received by some people at the colleges early Friday morning was a hoax and “a form of extortion.”
Officials in the Colorado Community College System say threats have been made against Arapahoe Community College, Aurora Community College, Denver Community College, Front Range Community College and Red Rocks Community College.
The Community College of Aurora has been placed on lockdown, so classroom instruction continues, but campus buildings and grounds are secured.
The other colleges were closed for the day.
In addition, the University of Colorado Boulder said that while there was no threat to its campus, it canceled all classes and activities as a precaution. CU Colorado Springs said it also closed for the day.
“We are working closely with campus security teams and law enforcement agencies to monitor the situation,” Colorado Community College officials said.
“Some colleges are currently in lockdown protocol. we encourage students, faculty and staff to check their institution’s website for campus information.”
Police in Westminster, Colorado, say officers made contact with a person of interest on Friday and that “it appears the threats are a form of abuse against this person.”