Multiple students at Curie High School in Chicago were being evaluated after eating a granola bar that may have contained an unknown substance, authorities said.
The Chicago Fire Department said it was called to the school just before 1 p.m. Multiple ambulances were requested at the scene.
Fire officials said at least four students ingested a granola bar that may have contained another substance in it.
Police said a 15-year-old girl and two 14-year-old girls became ill after "voluntarily ingesting a suspected cannabis-infused product" while inside the school.
Two of the students were taken to Mount Sinai Hospital Hospital, a third was transported to Holy Cross Hospital and one student refused treatment. The hospitalized students were listed in stable condition, according to the fire department.
Further information on what happened wasn’t immediately clear.