A sprawling North Carolina Army base says a power outage that lasted for hours was part of an unannounced training exercise.

Fort Bragg officials issued a statement Thursday saying the base purposely cut power throughout the installation "to identify shortcomings in our infrastructure, operations and security." They said they didn't announce the exercise so that they could test people's "real-world reactions" to the type of problems caused by an event such as a cyber-attack.

They said normal operations would be fully restored by later in the day.

The blackout began late Wednesday on the base that includes 52,000 soldiers, lasting into the next day.

During the outage, the on-base Womack Army Medical Center said it was operating under reduced capacity and certain appointments needed to be rescheduled.