(FILES) In this file photo taken on July 22, 2019, an image grab taken from a broadcast by Islamic Republic of Iran Broadcasting (IRIB), shows Iranian Revolutionary Guards in speedboats patrolling a tanker Stena Impero as it's anchored off the Iranian port city of Bandar Abbas. A US vessel fired warning shots at more than a dozen Iranian fast attack boats which buzzed close to a US Navy submarine and escort ships in the narrow Strait of Hormuz on May 10, 2021, the Pentagon said. / AFP / IRIB / - / RESTRICTED TO EDITORIAL USE - MANDATORY CREDIT "AFP PHOTO / HO / IRIB" - NO MARKETING NO ADVERTISING CAMPAIGNS - DISTRIBUTED AS A SERVICE TO CLIENTS  /NO RESALE/ NO ACCESS ISRAEL MEDIA/PERSIAN LANGUAGE TV STATIONS/ OUTSIDE IRAN/ STRICTLY NI ACCESS BBC PERSIAN/ VOA PERSIAN/ MANOTO-1 TV/ IRAN INTERNATIONAL"
Iranian Revolutionary Guard speedboats patrol near a tanker off the Iranian port city of Bandar Abbas. AFP

US coastguard ship fired warning shots at Iranian fast boats