Hundreds of students were forced to evacuate Theodore Roosevelt High School and at least six were rushed to the hospital after being exposed to pepper spray Friday.

Outside the school, students coughed and used oxygen masks to help them breathe after pepper spray was released into the cafeteria. A group of students was taken to St. Barnabas Hospital and treated for burning eyes and irritated arms and hands.

It is unclear who released the chemical and how they were able to get the spray into the building.

Fire officials say air quality in the school is back to normal. Students are expected to return to school after the long weekend.