A U.S. official has told Reuters that several fast-attack ships from Iran's Islamic Revolutionary Guards Corps (IRGC) came close to a U.S. Navy ship in the Strait of Hormuz, forcing it to change its course.
The official, speaking on condition of anonymity, said the Iranian boats on March 4 came within 600 meters of the U.S. Navy ship, the Invincible, and then stopped.
The Invincible was being accompanied by three ships from the British Royal Navy and all four ships in the formation were forced to change their course to avoid collisions.
The U.S. official said attempts were made to communicate over radio with the Iranian crews, but there was no response.
The official described the interaction as "unsafe and unprofessional."
The Invincible is a Stalwart class ocean surveillance ship -- known as a tracking ship -- that is equipped with antennas and electronics to support the tracking and launching of missiles and rockets.