Sonoma school lockdowns lifted after unspecified threat determined to be unfounded

A threat that was later determined to be unfounded caused a lockdown at four schools in Sonoma for about three hours Thursday afternoon.

At about noon, the Sonoma County Sheriff's Office announced that Sonoma Valley and Creekside high schools in Sonoma were on lockdown due to an unspecified threat to the schools, which share a campus.

The nearby Adele Harrison Middle School and Prestwood Elementary School were also locked down because of their proximity to the high school campus but weren't considered to be under any threat, sheriff's officials said.

At about 3 p.m., the lockdowns were canceled and people were allowed back into the neighborhood after deputies determined the threat was unfounded.