The U.S. Navy said Saturday that a U.S. helicopter "deployed flares" as Iranian Naval vessels in the Persian Gulf approached at high speed in an incident the Iranians have described as "provocative and unprofessional."
The official IRNA news agency said the incident occurred Friday afternoon and was similar to a confrontation earlier in the week.
It said the USS Nimitz and an accompanying ship approached an Iranian oil offshore platform and a helicopter from the ship hovered near vessels manned by Iran's elite Revolutionary Guard troops.
The incident came three days after a U.S. Navy patrol boat fired two warning shots near an Iranian vessel that American sailors said came dangerously close to them.
IRNA said that on Saturday the U.S. forces "committed the same act" when it sent choppers toward Islamic Revolutionary Guard Corps troops near the Resalat oil and gas field.
"IRGC navy patrol boat continued its mission, ignoring the unprofessional and provocative move by the US warship and the warship left the zone after a while," the IRGC said in a statement, IRNA reports.
The U.S. Navy said in its statement that its forces were conducting a routine patrol in international airspace when a U.S. helicopter spotted several Iranian naval vessels "approaching U.S. Naval forces at a high rate of speed."
"U.S. naval forces attempted to establish communications, with no response from the Iranian vessels," the statement said. "Shortly thereafter, at a safe distance, the U.S. helicopter deployed flares, after which the Iranian vessels halted their approach."
There have been sporadic clashes between U.S. and Iranian forces in the Persian Gulf in recent months, usually involving IRGC forces, which are separate from the Iranian military and report only to Iran's supreme leader.
In January, near the end of then-President Obama's term, the USS Mahan fired shots toward Iranian fast-attack boats as they neared the destroyer in the Strait of Hormuz, the mouth of the Persian Gulf through which a third of all oil trade passes by sea.
Iranian forces view the American presence in the Gulf as provocative. They have accused the U.S. Navy of unprofessional behavior, especially in the Strait of Hormuz.
Contributing: Associated Press.