In brief
Three Iranian tankers – Diona, Hero II and Sonia I – have crossed the U.S. blockade line in the Gulf of Oman, carrying a combined 3.8 million barrels of crude oil. The move comes amid a U.S. announcement that the blockade would be lifted, yet naval forces confirmed it remains in effect until a formal deal is signed. Maritime intelligence analysts view the action as a sign that Iran is confident the blockade is over, marking the first time these vessels have broadcast their positions since March. The ships, all owned by the National Iranian Tanker Company, represent the first Iranian oil exports in two months. The increased activity of Iranian-linked vessels worldwide underscores the evolving enforcement landscape under ongoing U.S. sanctions.
Three Iranian tankers carrying 3.8 million barrels of crude oil have crossed the U.S. blockade line in the Gulf of Oman, according to ship‑tracking data.
The vessels – Diona, Hero II and Sonia I – were all owned by the National Iranian Tanker Company, a conglomerate that has been sanctioned by the U.S. Treasury. Two of the ships broadcast their positions while crossing the line; a third turned on its tracker just after the blockade.
President Donald Trump announced on Sunday that the blockade of Iranian ports would be removed immediately, but U.S. naval forces later confirmed that it would remain in force until a deal with Iran is signed – expected to take place in Switzerland this Friday.
“This is a sign that Iran is confident the blockade is over, even if the U.S. has insisted it will be in place until Friday,” said Michelle Wiese Bockman, senior analyst at Windward Maritime Intelligence. The first time any of these tankers have broadcast their location since March, if they reach their destination they will be Iran’s first oil exports in two months.
Data from MarineTraffic shows Hero II and Sonia I departed Chabahar port in Iran on Tuesday, then passed the U.S. blockade line early Wednesday morning. Diona began broadcasting its location just beyond the line a day earlier. The three ships now travel westward into the Arabian Sea.
Collectively the vessels carry 3.8 million barrels of crude oil. They are not broadcasting their planned destinations, but analysts expect them to reach the Persian Gulf or the Indian Ocean for export.
The U.S. blockade has cut Iran’s crude exports to the lowest level in six years, at only 260,000 barrels per day in May – less than a fifth of the 2025 average of about 1.67 million barrels per day, according to Kpler.
At the same time, other Iranian‑linked vessels have been more active globally since the U.S. announced the pending deal. In the Strait of Malacca between Malaysia and Indonesia, the tankers Dan and Sinopa, also owned by the National Iranian Tanker Company, began broadcasting their positions on Tuesday. These vessels had not appeared on publicly available ship‑tracking platforms since early April.A tanker (Tifani) was previously intercepted by the U.S. in the Indian Ocean more than ten days after leaving the Gulf.
The U.S. has stated that enforcement of the blockade could occur outside the Gulf region. BBC Verify has previously reported American forces intercepting Iran‑linked vessels in the Indian Ocean, thousands of miles from the Gulf.
