A nuclear-powered U.S. attack submarine struck a suspected fishing vessel shortly after passing through the Strait of Hormuz in the Gulf on Thursday, damaging one of the submarine's periscopes but injuring no one, a Navy official said on the condition of anonymity.
The Navy's Fifth Fleet said in a statement the vessel appeared unaware of the incident, adding it "continued on a consistent course and speed offering no indication of distress or acknowledgment of a collision."
The USS Jacksonville, a Los Angeles-class, nuclear-powered submarine, did not appear to suffer further damage, the Bahrain-based Fifth Fleet said.
"The reactor remains in a safe condition. There was no damage to the propulsion plant systems and there is no concern regarding watertight integrity," it said.
The incident, which took place at 5 a.m. local time and is under investigation, follows an August collision between a U.S. guided missile destroyer and an oil tanker.
Iran has threatened to close the Strait of Hormuz if its dispute with the United States over its nuclear program escalates. Washington says it maintains naval forces in the Gulf to ensure security in the region.