Pleasanton police are investigating the origin of a bomb threat against Amador Valley High School that was sent by email to school principal Thomas Drescher Sunday.
Nicole Steward, the school district's communications coordinator, sent a notice of the threat in an auto-dialer to all Amador High parents this morning.
"We want you to be aware of the situation," Steward wrote to parents.
Once the email was read, Pleasanton police were immediately called to campus along with school administrative and custodial staff, Steward said.
"They conducted a comprehensive, hours-long search of the internal and external facilities," she said in her auto-dialed message. "Following the search, police declared the campus "clear."
Steward added that police and school district staff are confident that the Amador campus is safe. The school opened this morning on schedule with AP exams administered as planned.
Security was increased overnight Sunday and will remain at increased levels throughout the week.
According to Ltn. Jeff Bretzing, investigators are still trying to locate the sender of the email.
"The IP address has been sending us on a wild goose chase," he said.