Tucson police are investigating a "vague" shooting threat made against Palo Verde High School Thursday.
According to Tucson Unified School District spokeswoman Stefanie Boe, the threat is not believed to be credible.
KGUN9 has obtained a screenshot of the threat, which reads "If you hear the song 'Pumped Up Kicks' be careful. If anyone hears this on the intercom tomorrow at PV drop to the floor I'm shooting up the school."
Classes started at 9 a.m. Thursday at the school, 1302 S. Avenida Vega. Extra security will be on campus out of an abundance of caution, Boe said.