Iran has blacklisted 45 vessels, including oil tankers owned by South Korean shipping companies, for allegedly violating Hormuz Strait passage regulations. Iran warned that it could impose fines or seize cargo from these ships, and that all ships involved in transshipment could also be subject to action. The sanctions target include very large crude carriers (VLCCs), LNG and LPG carriers, and product tankers. Iran's move comes amid heightened tensions as the United States has threatened strong sanctions against Iran.