AMHERST, Va. — Amherst County officials say all public secondary schools are closing temporarily after a COVID-19 outbreak.

Superintendent Rob Arnold says a person who tested positive and entered a building without notifying staff is the source of many positive cases.

News outlets report that the Virginia Department of Health recommended the closure. Schools will be closed from Thursday until at least Sept. 2.

Elementary schools aren’t affected. Students must provide a negative COVID-19 test result before returning Sept. 2.

Students who refuse can return Sept. 7.

School officials urged parents to monitor their children for COVID-19 symptoms and notify their child’s school if a child tests positive or is exposed to it.