A cargo vessel under contract with the US Navy fired warning shots on two small boats which approached the ship in the Gulf and failed to respond to radio communications, the US Navy said Friday.
The small speed boats left the area after the warning shots and the US ship Westward Venture received radio contract from a unit of the Iranian Coast Guard, the Navy's Fifth Fleet in Bahrain said.
The Navy could not confirm that the boats during Thursday's incident were Iranian, dpa reported.
Iran said it had not had a confrontation with the United States Navy in the Gulf, official news agency IRNA reported Friday night.
IRNA quoted an Iranian Navy spokesman as saying there was no confrontation between Iranian boats and a US vessel in the Gulf.
US Navy ships in the Gulf have in the past had encounters with small Iranian boats.
One of the bigger incidents between the two countries took place in January, when three Iranian fast boats came dangerously close to three US warships in international waters in the Strait of Hormuz before vanishing as one of the US vessels was preparing to open fire.