Iranian Islamic Revolution Guard Corps Navy (IRGCN) vessels approached U.S. Navy vessels on Wednesday in a "dangerous and harassing" manner, the U.S. Navy said in a statement.
Eleven IRGCN vessels repeatedly approached U.S. navy vessels in international waters of the North Arabian Gulf while the U.S. Navy was carrying out exercises, the statement from the Bahrain-based Fifth Fleet said, adding that the actions were "dangerous and provocative".
No mention of the incident was found in Iranian media.
A day earlier, suspected Islamic Revolution Guard Corps (IRGC) masked armed men boarded a Hong Kong-flagged oil tanker near the Strait of Hormuz and soon left the vessel.
TankerTracker intelligence and maritime information group reported that the vessel actually belongs to a Chinese company. The crew were reportedly also Chinese.
It is possible that the IRGCCN boarded the vessel and then realized it belonged to a Chinese company and decided or were ordered to abandon the ship.
China is one of the few important allies the Islamic Republic still has and a customer of its oil.
IRGCN in the past often harassed U.S. navy vessels in the Persian Gulf and the Sea of Oman, but in the last two years there were few reports of overt provocations. Instead, Iran is suspected to have been behind attacks on oil tankers in 2019 and a missile attack on Saudi Arabia's oil installations.
U.S. sanctions have choked Iran's economy and the U.S. is opposing an Iranian loan request from the International Monetary Fund.