They say the suspect was shot and killed by law enforcement.
That evolved to multiple victims and multiple victims at the elementary school.
KCRA reports officers are investigating at least five scenes in the school and the surrounding area.
The shooter, whose age or name has not yet been given, was shot and killed by police at the scene.
The shooting was first reported around 8:15 a.m. PT.
Officials were not available to comment on the shooting, but emergency radio traffic included multiple gunshot victims in the shooting.
He heard there were people injured, but those were unconfirmed reports.
The nearby Rancho Tehama Airport was placed on lockdown. Rancho Tehama is southwest of Red Bluff.
Students at Rancho Tehama Elementary are being evacuated to the Rancho Tehama Recreation Hall.
"Our doors are locked", she said.
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