GREELEY, Colo. (CBS4)– Investigators believe an online threat to schools in Greeley is nothing more than a hoax. The threat started as a Facebook post warning of clowns carrying out shootings.

Them threats follow reports in several other states where clown sightings have been reported that leave some neighborhoods uneasy.

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The instances in Greeley quickly gained traction on social media and even kept some students home from school on Tuesday.

“I only had five kids in class. It’s just a waste of time for teachers,” said Northridge High School student Mason Henkel.

Northridge High School in Greeley (credit: CBS)

Northridge High School in Greeley (credit: CBS)

In South Carolina, clowns have been reported to police after allegedly trying to lure children into the woods.

Similar instances have been reported in Alabama and North Carolina.

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Police in Denver have investigated one reported instance of a clown sighting and say it’s best to be cautious.

“If you see anything that unusual do your best to avoid any interaction and obviously call police, we will definitely come check it out,” said Denver Police Department spokesman Doug Schepman.

In Greeley, despite the lack of credibility, police and the Weld County District Attorney are taking the claims seriously.

“Whether it’s a copy cat or somebody making up these threats as an original thought in their mind, they still need to be held accountable,” said Weld County District Attorney Michael Rourke.

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Investigators believe the hoax was started by a 15-year-old student. Additional resource officers were staffed at schools in Greeley on Wednesday.