TUCSON (AP) -- About 850 students at Tucson High School were evacuated from the school after a threat to the campus was made on Tuesday morning.
Tucson police spokesman officer Chuck Rydzak says a bomb threat was made just before 9 a.m. and students were evacuated to the football field.
Students were taken to the McKale Center at the University of Arizona, a nearby school or allowed to drive home if their parents approved.
Five explosive-sniffing dogs searched the campus but found nothing and it reopened at about 2 p.m.
Rydzak says police didn't know if the threat was credible but wanted to make sure the school was safe.