The U.S. Navy on Monday was forced to fire warning shots several times after a group of 13 Iranian ships harassed the American vessels in the Strait of Hormuz, the largest such encounter in more than a year, according to the Pentagon’s top spokesperson. Islamic Revolutionary Guard Corps Navy (IRGCN) speed boats armed with machine guns “conducted unsafe and unprofessional maneuvers,” approaching U.S. ships “at a very fast speed” as the Navy and Coast Guard boats were escorting the submarine USS Georgia as it was transiting on the surface toward the Persian Gulf, press secretary John Kirby told reporters.