The Seawolf-class nuclear-powered attack submarine USS Connecticut struck an object while submerged in international waters in the Indo-Pacific region on October 2, the US Navy said in a statement five days after the incident.
The navy assured that there were no life-threatening injuries among the crew.
Connecticut remains in a safe and stable condition, the navy added. The submarine's nuclear propulsion plant and spaces were not affected and remain fully operational.
The extent of damage to the remainder of the submarine is being assessed and the incident will be investigated, the navy clarified.