The U.S. Navy says 11 vessels of Iran’s Islamic Revolutionary Guard Corps (IRGC) made “dangerous and harassing approaches” toward U.S. naval ships in the Persian Gulf.
The U.S. ships were in international waters carrying out exercises at the time of the incidents on April 15, the U.S. 5th Fleet said on Twitter.
One of the IRGC vessels came within about 10 meters of one of the U.S. ships, it said, while another came within 50 meters of a U.S. ship.
The ships took “actions deemed appropriate to avoid collision,” according to the fleet, which said the IRGC vessels “maneuvered in an unsafe & unprofessional manner.”
The fleet said there were no injuries, but it added that the IRGC ships’ actions violated “both proper seamanship in accordance with the rules of the road & due regard for the safety of other vessels in the area as required by international law.”
The 5th Fleet, based in Bahrain, also released photos showing one of the vessels it says was targeted, the USS Lewis B. Puller, with smaller ships around it.
The incident comes a day after unidentified armed men boarded a Hong Kong-flagged oil tanker near the strategic Strait of Hormuz.
The United Kingdom Maritime Trade Organization said on April 14 that the vessel was boarded while anchored just off the Iranian coast in the Sea of Oman, but added that the ship was later released.
U.S. Secretary of State Mike Pompeo said he had discussed the incident with the Pentagon.
“We’re evaluating how best to respond and how best to communicate our displeasure with what…took place,” Pompeo said in an interview on Fox News.
Close interactions with Iranian military vessels have occurred in the region in the past, drawing warning shots from U.S. Navy ships when Iranian vessels got too close.
Tensions between Iran and the United States increased in January after the United States killed Iranian Quds Force commander Qasem Soleimani in a drone strike in Iraq.
Iran retaliated with a rocket attack on the Ain Al-Asad Air Base in western Iraq where U.S. forces were stationed. No U.S. troops were killed but more than 100 were later diagnosed with traumatic brain injury.