U.S. forces fired on a Panama-flagged vessel early Tuesday after the ship allegedly attempted to break the American naval blockade of Iranian ports, The Wall Street Journal reported, citing a U.S. official.
According to the official, a U.S. military helicopter fired at the vessel's rudder after its crew ignored warnings from American personnel enforcing the blockade.
There were no immediate reports of casualties from the incident, which took place before dawn.
The U.S. official said the vessel appeared to be trying to transfer its crew to another civilian ship after being hit.
Maritime security firm Vanguard separately reported earlier Tuesday that a Panama-flagged container ship named Vela Nova had been struck by a missile fired from a helicopter while traveling west through the Gulf of Oman.
The vessel was about 71 nautical miles from the coast of Pakistan when the incident occurred, according to Vanguard.
"The missile struck the vessel, causing a fire that was subsequently extinguished," the company said in its initial report.
Vanguard said all 17 crew members were accounted for following the strike.
The incident comes as the Trump administration steps up enforcement of its blockade of Iranian ports as part of efforts to increase economic pressure on Tehran.
The U.S. campaign is aimed at restricting Iran's oil revenues and pressuring the country to reach an agreement to end the war.
The blockade has previously resulted in fatalities.
In June, three Indian sailors were killed during a U.S. operation to enforce the blockade of Iran, according to an Indian official cited at the time.
Those deaths were the first reported fatalities resulting from the American effort to deprive Iran of petrodollars and pressure Tehran into reaching a deal to end the conflict.