SPRINGFIELD, Ill. (KTVI/WGN) — As many as 19 Illinois counties received school threats on Wednesday, in what is being referred to as “swatting,” Illinois State Police said in an update Wednesday afternoon.

Totaling 21 calls, several Illinois communities across the state received swatting threats, dangerous and illegal fake calls about an active shooter situation, directed toward schools, a spokesperson from Illinois State Police told WGN News.

All threats have been unfounded.

“The Illinois State Police Statewide Terrorism and Intelligence Center currently has no information concerning credible threats related to school safety. Law enforcement, public safety, and private sector security officials are encouraged to remain vigilant and report all suspicious behavior to local police agencies,” the statement read.

Chicago and Aurora reported swatting calls on Wednesday, in addition to Rockford and Springfield, according to Nexstar affiliate WTVO

Several reports of threats and swatting were being investigated at Illinois schools around the St. Louis region.

Counties in Illinois that have reported calls Wednesday as of 3 p.m. include:

The cause of the rise in threats or the source is not yet clear.