Naval Hospital Beaufort officials are telling patients to get their prescriptions filled and schedule their appointments before the start of a security exercise that will all but shut down the base for three days.

Access to the Naval Hospital will be limited to those with medical emergencies, essential personnel and on-base housing residents from noon today until noon Saturday as the base participates in Exercise Solid Curtain/Citadel Shield 2012, the Navy's annual anti-terrorism exercise, hospital spokeswoman Regena Kowetz said.

The drill tests how base security responds to several simulated scenarios. Kowetz said it is not a response to the Feb. 24 incident in which Kalvin Hunt, a 26-year-old Marine, allegedly fled the hospital, stole a Port Royal firetruck and struck and killed a pedestrian. Hunt later was charged with murder. Hospital officials have declined to say why he was at the base, citing patient privacy laws.

"This exercise is an annual exercise, which has been conducted regularly since 1999 and is taking place at every naval installation in the continental United States," Kowetz said. "We are testing our ability to maintain a high state of readiness to safeguard our installations, keep our patients, visitors and staff safe from all threats, and deter real-world attacks."

Kowetz said the drill will result in increased security -- and possibly delays and traffic jams -- near the base's main gate off Ribaut Road in Port Royal.

"Our security and emergency-management staff has been in contact with officials at Beaufort County's emergency management department to make sure they are aware of the exercise and the potential impact it could have on traffic," Kowetz said.

Follow reporter Patrick Donohue at twitter.com/OnBaseBeaufort.