The Iranian ships kept operating close to the US vessels despite repeated bridge-to-bridge warnings and the use of loud-hailer devices. In response, the Firebolt fired warning shots, Rebarich said, at which point the Iranian ships backed away to a safe distance. The incident marks the second time this month that ships from the IRGC Navy have harassed US ships in the Persian Gulf. In addition, the actions of the Iranian ships ignored internationally recognized maritime customs and international regulations for preventing collisions at sea. The Coast Guard ships are part of Patrol Forces Southwest Asia, the largest Coast Guard unit outside the United States.