Pearl Harbor Naval Shipyard is on lockdown amid reports of an active shooter and multiple victims.
Several civilians are among those hurt, according to local reports. The incident is said to have taken place at Drydock 2.
Personnel at the base have been told to take cover, Hawaii News Now reports.
Emergency crews raced to the scene at around 2:30pm local time. Text messages are said to have been sent those in the area alerting them of the danger.
Footage from the scene show law enforcement and first responders at the scene.