(CNN) -- The University of Oklahoma in Norman briefly shut down Wednesday after a report of a possible shooting that apparently turned out to be a false alarm, the university's president said.
"At this time, there is no evidence that shots were fired. Classes are going on as normal in all other buildings except Gould Hall," President David Boren said Wednesday afternoon. "Additional search of Gould Hall being conducted just in case. It appears to have been a false alarm."
Earlier Wednesday, no evidence had been found of any shots being fired, and no injuries had been reported, school spokeswoman Catherine Bishop said.
After telling students to take shelter for more than 30 minutes, the school later announced that normal campus operations had resumed -- except at Gould Hall, the site of the reported shooting, "where additional checking is continuing," the school tweeted.
Gould Hall houses the university's College of Architecture.
Both the Norman and campus police responded quickly as did emergency personnel, the school tweeted.
Boren told students the incident may have been a false alarm caused by a machinery backfire, independent student newspaper The Oklahoma Daily reported on Twitter.
Maj. Bruce Chan of campus police told CNN there was a report of shots fired in the Gould Hall area of campus.
The incident took place at around 11:20 a.m. local time (12:20 p.m. ET) while classes were in session.
Students and faculty were alerted via text.
On Tuesday, a gunman shot and killed a man at Purdue University in Indiana.
CNN's Sara Pratley and Mayra Cuevas contributed to this report.