Tensions between Iran and the outside world have escalated since an attack on four tankers on May 12 near the Strait of Hormuz, which was followed by an attack on two more tankers on June 13. Both attacks occurred in the Gulf of Oman. The Persian Gulf flows through the Strait of Hormuz into the Gulf of Oman.
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https://iranprimer.usip.org/blog/2019/jun/13/tanker-crisis-gulf