Iran has placed 45 oil, gas and petroleum-product tankers on a non-compliance list over alleged violations of its rules for navigating the Strait of Hormuz, raising the prospect of fines, detention and cargo seizures as tensions around the strategic waterway intensify.
The blacklist, announced by Iran’s newly established Persian Gulf Strait Authority, covers a broad range of vessels, including very large crude carriers, liquefied natural gas (LNG) tankers, liquefied petroleum gas (LPG) carriers and clean-product vessels.
Iran also warned that ships conducting ship-to-ship transfers with any of the blacklisted tankers could themselves be added to the list, potentially widening the impact of the latest restrictions across the shipping network serving the Persian Gulf.
The move comes shortly after Washington threatened Iran with what it described as the “toughest sanctions in history”, while Tehran has warned that any further U.S. pressure could trigger a “devastating” response.
Iran has not publicly detailed which specific rules the 45 vessels allegedly breached. However, Tehran has previously maintained that shipowners should obtain clearance before passing through the Strait of Hormuz and has sought payments for security and other maritime services.
The latest action therefore adds another layer of uncertainty to a waterway that has already experienced a severe decline in shipping activity since the war disrupted regional tanker movements.
Kpler data cited in the reports showed that only four commodity vessels crossed the strait on Sunday, compared with 13 the previous day. Separately, UK Maritime Trade Operations estimates that AIS-detected traffic remains about 90% below pre-war levels.
The Strait of Hormuz is a critical artery for global energy markets. Before the conflict disrupted shipping, about one-fifth of the world's crude oil and LNG supplies moved through the waterway.
Despite the sharp reduction in traffic, some oil flows have continued. U.S.-coordinated efforts to move tankers through the strait and transfer cargoes to larger vessels waiting outside the waterway have helped sustain part of the region's exports.
U.S. Energy Secretary Chris Wright said on Friday that the seven-day average of oil leaving the Strait of Hormuz had risen above 8 million barrels per day. He attributed the continued movement of crude through the waterway to the presence of the U.S. Navy.
Iran's latest blacklist could complicate those efforts if vessels associated with the targeted tankers face additional restrictions or if more ships become subject to scrutiny because of their involvement in ship-to-ship transfers.
The vessels named by Iran include ships associated with major Gulf shipping interests, including United Arab Emirates-based ADNOC Logistics & Services, its Navig8 Tankers subsidiary and Saudi Arabia's national shipping company Bahri.
Ships linked to Klaveness Ship Management, Stolt Tankers and South Korea's Sinokor are also on the list.
ADNOC did not immediately comment on the blacklist, while other companies named in the report had not responded to requests for comment at the time of publication.
The Persian Gulf Strait Authority said cargo owners should consult its updated list of vessels classified as non-compliant for Gulf-related voyages. It also said companies seeking to have vessels removed from the list must submit requests, accompanied by explanations, to Iranian maritime authorities.
The escalation comes as the United States prepares another round of economic measures against Tehran. U.S. Treasury Secretary Scott Bessent is expected to unveil the measures, described by Washington as an “economic D-Day”, amid Iran's increasingly forceful warnings over the consequences of further pressure.
Iran had also threatened to prevent oil from leaving the Persian Gulf if Washington proceeded with the new economic offensive.
The timing of the blacklist adds to uncertainty over the amount of Iranian crude available to international buyers. Iranian oil shipments to Asia have reportedly fallen sharply ahead of the expected U.S. measures, potentially reducing the volume of Iranian barrels directly exposed to further sanctions.
For the shipping industry, however, the immediate concern is the growing number of vessels facing restrictions around Hormuz. Any expansion of the blacklist to ships involved in transfers with the 45 named tankers could further complicate efforts to maintain energy flows through a waterway already operating well below normal traffic levels.
The 45 vessels identified by the Persian Gulf Strait Authority are:
- Kiku — IMO 9329796
- Mubaraz — IMO 9074626
- Minoan Pioneer — IMO 9471630
- Hafeet — IMO 9928009
- Al Rekayyat — IMO 9397339
- Wedyan — IMO 9524970
- Cyprus Prosperity — IMO 9595216
- Al Rawdah — IMO 9734513
- Rasheeda — IMO 9443413
- Lebrethah — IMO 9976927
- Lila Vadinar — IMO 9324100
- Maha Roos — IMO 9231004
- Gfs Galaxy — IMO 9401271
- Al Bahyah — IMO 9937799
- Mombasa B — IMO 9739501
- Stolt Magnesium — IMO 9739317
- Al Watan — IMO 9615030
- Navig8 Messi — IMO 9482859
- Singapore Prosperity — IMO 9419967
- Disha — IMO 9250713
- Gaslog Shanghai — IMO 9600528
- Lubna — IMO 9489065
- Hazi 1 — IMO 7802598
- Ryujin — IMO 8206818
- Anna Barbara — IMO 9407500
- Sunbird Arrow — IMO 9323821
- Minoan Dignity — IMO 9294484
- Maria — IMO 9917828
- Kavomaleas — IMO 1042823
- Mardan — IMO 9360453
- Sweden Prosperity — IMO 9588392
- Jarnain — IMO 9823546
- Kaifan — IMO 9656046
- Nissos Kea — IMO 9920758
- Rotterdam Energy — IMO 9508859
- Al Hamra — IMO 9074640
- Umm Al Ashtan — IMO 9074652
- Marigold LNG — IMO 9230062
- Banastar — IMO 9228045
- Navara — IMO 9241798
- Nissos Heraclea — IMO 9419618
- Blue Star 1 — IMO 9215115
- Ashley — IMO 9258466
- Mraweh — IMO 9074638
- Al Lulu — IMO 9583627