Schools in a Shenandoah Valley county in Virginia are closed and a weekend activities have been canceled amid an angry backlash about a school lesson involving the Islamic faith.

Augusta County school officials said they decided to cancel classes Friday based on the recommendations of law enforcement officials and the school board.

While school officials said they had not received any specific threats, they were alarmed by the volume and tone of the complaints, including some from outside Virginia. In response, additional police were stationed at county schools Thursday.

Anger over the lesson has escalated since a teacher at Riverheads High School had students in her class complete an assignment one week ago. It involved practicing calligraphy and writing a statement in Arabic.