Updated at 2:28 p.m. ET
An administrative building on the campus of a San Francisco Bay area university was reopened after police investigated reports of a gunman inside, San Jose State University announced on its Twitter account.
The university's police department had set up a perimeter around Sweeney Hall, which houses the office of the president, while officers searched inside, CBS San Francisco station KCBS-AM reported.
"A thorough search of Sweeney Hall did not reveal anything," the university announced. "Sweeney Hall is open for business. Resume normal activity."
The university sent out a text alert to students at 9:22 a.m. advising them to shelter in place because of the situation. A university spokeswoman later clarified the shelter in place applied only to Sweeney Hall.
The alert had advised students to stay away from Sweeney Hall area and said the rest of the campus was open.
There were no reports of injuries.