BERKELEY -- Police have searched more than half the buildings at UC Berkeley following a report of a bomb in an undisclosed location Tuesday morning, police said.

Nothing suspicious has been found, police said.

Officials said a campus operator received a call on the general university line about 9:20 a.m. Tuesday from someone who said, "There is a bomb on campus."

After a preliminary search, authorities decided not to evacuate buildings until the report or a location could be verified, authorities said.

Campus officials released information about the threat about 1:10 p.m.

"The general campus community has been informed and has been asked to report anything suspicious," said UC police Lt. Marc Decoloude. "We will continue to go through all buildings on the grounds in search of anything suspicious."

UC Berkeley Police Capt. Stephen Roderick said that at least 20 officers and four police dogs -- some on loan from the Alameda County Sheriff's office -- searched the campus.

As of 5 p.m. Tuesday, at least 80 buildings had been searched and Roderick said officers still had at least another 80 buildings left to search.

Officers and dogs will remain on campus Tuesday night until they feel "every place that is accessible to the public is safe," Roderick said.

Campus officials believe the call is a hoax, as similar threats have been reported by at least five other public universities in the past month, including

If anyone sees something suspicious on campus, they should report it to UCPD at 510-642-6760.

Contact Erin Ivie at 925-847-2122. Follow her at Twitter.com/erin_ivie. Contact Kristin J. Bender at kbender@bayareanewsgroup.com. Follow her at Twitter.com/kjbender.