Local residents who have registered for the CodeRed emergency alert system will be called or texted Thursday to test the system.

The messages will instruct people how to register for the system in an attempt to work out any technical issues in the event of an actual emergency, Warren County Emergency Management Director John Elfer said.

Warren County residents inside and outside Vicksburg city limits may sign up on either local government’s website through emergency management links. Registrants must enter an address and at least one phone number, then have a choice of weather-related and other alerts they want to receive.

Weather alerts follow warnings issued by the National Weather Service for tornadoes, severe thunderstorms and flash floods.

More than 400 people in Warren County registered last week as non-city addresses were accepted for the first time.