STUTTGART, Germany — Patch High School and Patch Elementary School were evacuated for about three hours Friday, following a written bomb threat discovered on the premises, base officials said.

U.S. Army Garrison Stuttgart Department of Emergency Services and German police searched the schools, said Mark Howell, USAG Stuttgart spokesman. He would not provide other details. The school building evacuated is shared by the elementary and high schools.

Students and faculty were taken to the base theater and gym during the evacuation. An “all clear” was announced at 2:30 p.m., three hours after the school building was evacuated.

Some parents were seen picking up their children early, but buses ran and after-school programs operated as scheduled, Howell said.

An investigation is continuing, Howell said.

Migrated