Dover Air Force Base will be conducting an Active Shooter Exercise with local and state law enforcement on Monday. During the exercise standard security measures will be implemented, including gate closures. Anyone travelling onto or off the base should anticipate delays. Officials say the exercise will be a real-world simulated threat, so people may hear sirens activated both on and off the base, but there is no cause for alarm. DelDOT will display signage warning of potential traffic delays from the exercise. Dover AFB is required by Secretary of Defense directives to hold two active shooter exercises annually.