WASHINGTON (AFP) - An unidentified gunman shot and wounded six people at a FedEx facility in the US state of Georgia, US media reported Tuesday morning.

Atlanta's CBS4 news station said police were alerted shortly before 6am about the shooting in a warehouse in the city of Kennesaw, 40km northwest of Atlanta.

The building was evacuated as police launched a search for the suspect, the station said.

"We have multiple victims at this time that have been transported to a local area hospital," Mike Bowman, officer with the Cobb County Police Department, said in a statement reported by The Atlanta Journal-Constitution.

"We have multiple agencies assisting us with this incident. The area around the building has been secured and the officers are now clearing the incident location. This is still an active and fluid situation."

FedEx said in a statement it is aware of the situation.

"Our primary concern is the safety and well-being of our team members, first responders and others affected. FedEx is cooperating with authorities," it said.

Six people were hospitalised and one was undergoing an operation, according to CNN.