Two fires were discovered at Hastings High School Wednesday, making it four fires set at the school in the past three days.
Today's fires were set while most of Hasting's firefighters battled a large fire in the city's downtown.
Wednesday morning school officials extinguished a fire in a school parking lot. The fire was set to a ball of chicken wire stuffed with combustible materials.
Firefighters were called to the school about 11 Wednesday morning for a fire in the school library. School officials put out the fire before fire personnel arrived and before damage occurred.
On Monday, a paper towel dispenser was set on fire in a boy's restroom. Tuesday's fire was set in a trashcan in a janitor's closet.
Fire investigators say Monday and Tuesday's fires were set intentionally. No comment was made whether today's fires were set on purpose.