The incident began around 2.20 pm on Monday, when the woman called the police's regional command center.
During the conversation, he stated what the police describe as a "suspected threat to the school".
Patrols were sent out and the school was contacted and staff were asked to enter the school building with the children and lock the front doors as a precaution.
It was calm at the scene and the woman was found after a while and arrested, suspected of making illegal threats.
After questioning, prosecutors decided she would be arrested.