A high school in Delaware County has been declared safe after being evacuated due to a bomb threat.

Students and staff at Strath Haven High School were moved this morning to the district's middle school while authorities investigated, a message on the Wallingford-Swarthmore School District's website said.

Police searched the school for about two hours. Students have returned to the building, and afternoon classes, as well as after-school activities, are proceeding as planned.

A student reported the threat to school officials this morning, the district said.