A pep rally scheduled at Middletown High School on Friday has been postponed after someone used AirDrop to send students a scary threat about Friday's pep rally.

The district says it happened Thursday afternoon in the high school cafeteria.

MORE: Response from school

Someone told a security officer about a photo they received via AirDrop on their iPhone.

The caption said: "On 9/16...The school will be shot up during the pep rally if u don't wanna get lit up don't show up AK-17 will be used."

The school team held the students in place, but they say since the photo was shared so many times, it's impossible to know where it started. 

The district says it will continue to work with police to investigate, but in the meantime, it wants parents to talk to their kids about how serious these threats are and look into limiting AirDrop on their kids' phones.