DOYLESTOWN, Pa. (AP) — Police officers are on hand after a threat referencing Sept. 11 was found written in a bathroom stall in a Pennsylvania school.

Officers are patrolling Central Bucks West High School in Doylestown as a precaution Monday.

It's not clear what the threat said. But principal Timothy Donovan told parents the situation was promptly addressed to ensure the safety of students and teachers.

The school will excuse the absences of any students if parents decide to keep their children home....