US Marines Board Iranian Tanker in Latest Blockade Enforcement

According to U.S. Central Command, U.S. forces have diverted 91 vessels since the start of the blockade against Iran on April 13.

U.S. Marines with Maritime Raid Force, 31st Marine Expeditionary Unit, conduct fast rope training aboard the forward-deployed amphibious assault ship USS Tripoli (LHA 7) in the U.S. Central Command area of responsibility, April 14, 2026. U.S. Marine Corps photo

U.S. Marines boarded an Iranian oil tanker on May 20 amid concerns the vessel was attempting to violate a U.S. blockade of Iran’s ports.

U.S. Central Command (CENTCOM), which oversees military operations in the Middle East, said Marines from the 31st Marine Expeditionary Unit boarded the Iranian-flagged M/T Celestial Sea.