“Law enforcement is on site and looking into this threat,” a district statement says. “We have sent a message to all of our bus drivers to return students home, and will be going to the bus routes that were not picked up yet to tell students to return home.”

Students already at school are staying with staff at a safe location, the statement says.

“Once law enforcement tells us it is safe to do so, we will be contacting the families of all students on campus to inform you of the best time and location to pick up your students,” the district says.

The closure effects the high school, middle school and three elementary schools – Lakewood, English Crossing and Cougar Creek.