The lunch periods at Marshalltown High school were interrupted this morning. Marshalltown superintendent Marvin Wade says a smoke bomb went off in the cafeteria around 11:05.

Wade says all the students were temporarily evacuated as a precaution. Police and fire officials removed the device and smoke from the cafeteria and lunch periods were continued. No one was injured, and police are still trying to figure out who set off the device.

Radio Iowa