Schools in a Virginia county have closed after a class assignment asking students to practise Arabic calligraphy using a Muslim statement of faith sparked an outcry from parents and threats from outside the district.
Augusta County Public Schools officials said no specific threat of harm had been made against students in the district, located in Virginia's Shenandoah Valley about 240km southwest of Washington.
But the volume of calls and emails related to the high school class lesson and concerns over their "tone and content" prompted the school closures, according to a statement on the district's website on Friday.
The outcry over a lesson based on a brief Muslim text appeared to reflect a current mood of anxiety and distrust of Muslims among some Americans.
That follows a December 2 shooting in San Bernardino, California by a married couple who killed 14 people and were said by authorities to be inspired by militant Islamism, and attacks in Paris by Islamic State militants on November 13 that killed 130 people.
"We regret having to take this action, but we are doing so based on the recommendations of law enforcement and the Augusta County School Board out of an abundance of caution," the school district statement said.
Extracurricular activities on Thursday and through the weekend were also cancelled for the district's approximately 10,000 students.
The backlash in Augusta County was triggered by an assignment last week in a world geography class at Riverheads High School in Staunton, local news reports said.
As part of a study of the Middle East, a teacher instructed her students to copy a Muslim statement of faith written in Arabic and intended to show the complexity of calligraphy, the school superintendent told the News Leader newspaper.
The statement translates as "There is no God but Allah, and Mohammad is the messenger of Allah."
Some parents have accused the teacher, Cheryl LaPorte, of trying to indoctrinate students with Islam and are calling for her to be fired.
The school district said in its statement that students would continue to learn about world religions as required by the state but a non-religious sample of Arabic writing would be used in the future.
"No lesson was designed to promote a religious viewpoint or change any student's religious belief," the statement said.
LaPorte said she had received overwhelming support from former students, colleagues and others in the community.
"All I want now is time for our community to heal," she said in an email to Reuters.
