THORNDIKE, Maine (AP)   Police in Maine say a student has released an aerosol self-defense spray in school, causing an evacuation.

The Waldo County Sheriff’s Office responded Wednesday to a possible chemical release affecting as many as 20 students at the Mount View school complex in Thorndike.

Authorities say a school resource officer learned that the source of the chemical odor might have been an aerosol self-defense spray. Students and staff were evacuated from the building while emergency responders worked to identify the substance.

Authorities say they confirmed a student released the product inside the school. It was not immediately clear why. The investigation is ongoing.