Active Shooter Threat Alert Reported at Oklahoma University

Students walk on campus between clases at the University of Oklahoma in Norman, Okla., on March 11, 2015. Brett Deering/Getty Images

The University of Oklahoma confirmed that its campus was secure following an alert nearly 90 minutes earlier about an active shooter that prompted a lockdown on Friday night.

The university issued a tweet at 9.45 p.m. notifying students and staff about the situation at the Van Vleet Oval. The tweet advised everyone to take immediate action.