CORVALLIS, Ore. -

A telephoned bomb threat Thursday night prompted the evacuation and search of all residence halls on the Oregon State University campus, a roughly two-hour process that turned up nothing suspicious, Oregon State Police said.

Corvallis police and Benton County sheriff's deputies joined OSP troopers checking the dorms for any suspicious objects or packages.

Around 7:15 p.m., an unidentified person called OSU Department of Public Safety with the threat but didn't identify a specific residence hall, troopers said.

By around 9:30 p.m., OSP reported all of the dorms had been checked and cleared, with nothing suspicious found, and students were being allowed to return.

Displaced residents had been instructed to go to either the Valley Library or Memorial Union until advised to return to their residence hall.