Members of the Bureau of Alcohol, Tobacco, Firearms and Explosives and the FBI reacted to what was happening at the scene, in which the suspect was killed.
A spokesman for the US Navy said there were "an unknown number of wounded" who were taken to hospital for treatment, and that the base is still closed.
A local hospital spokesman said nine victims of the accident had been admitted, but their condition was not known.
The incident is the second at a naval base in a week.
A 22-year-old sailor in the military opened fire on three civilians working in a Pearl Harbor arsenal near Honolulu, Hawaii.
American, killing two people before shooting himself. The US military confirmed an active shooting incident at a naval air base in Pensacola, Florida.