NAPERVILLE, IL (WCMH) — Several students in Illinois were taken to the hospital after they say they ate gummy bears laced with an unknown substance.

“A lot of people told me there were kids going to the hospital on stretchers and everyone was really sick from the gummy bears,” one student told WLS.

A total of 13 teens at Naperville North High School received medical treatment for various levels of discomfort including rapid heart rate, dizziness and dry mouth.

One teen was taken into custody but was later released without any charges after being questioned by police.

According to police, the teens all ate the gummy bears voluntarily, but it isn’t clear if they knew the candy was laced. Police continue to investigate what substance was used to lace the gummy bears.