NORMAN, Oklahoma -- The University of Oklahoma was under high alert late Friday night after authorities received reports of an active shooter on campus.
The Norman, Oklahoma, campus first alerted followers at about 9:25 p.m. on the university's Twitter account.
"OU-Norman Emergency: There is an active shooter at the Van Vleet Oval. Take immediate action now. Run Hide. Fight!" the university tweeted.
Van Vleet Oval is a central green space for outdoor activities, according to OU.
A follow-up tweet at 9:45 p.m. stated the university's police department was investigating possible shots fired, urging people to avoid the South Oval area and to shelter in place. OU reaffirmed that investigation in a tweet 19 minutes later.
Shortly before 11 p.m. the school tweeted that campus police had issued an all clear.
"After a thorough search, no threat was found. There is no threat to campus. Alert has been canceled," they wrote.