There are "multiple fatalities" from a shooting in Jacksonville, Florida, Saturday afternoon, Mayor Donna Deegan told CNN.

She said more details would be coming from the Jacksonville Sheriff's Office shortly.

Deegan also told CNN affiliate WJXT the shooter was barricaded inside a Dollar General store on Kings Road. It was not immediately clear if victims were shot inside the store or at a different location.

Jacksonville Fire and Rescue Department spokesperson Eric Prosswimmer told CNN that the department was "on standby" to treat victims but could not share any information about how many people were hurt.

Jacksonville is located in northeast Florida, about 35 miles south of the Georgia border.

This is a developing story and will be updated.