The US military disabled the Gambia-flagged cargo vessel Lian Star on Saturday by firing a missile into its engine room after it ignored more than 20 warnings while attempting to reach an Iranian port — the sixth ship stopped since the US naval blockade of Iran began on April 13, and the clearest demonstration yet of how the blockade is being enforced while ceasefire negotiations continue.
The US military stopped a merchant vessel trying to break through its blockade of Iranian ports by firing a missile into its engine room, the US Central Command said on Saturday. The Gambia-flagged cargo ship Lian Star ignored more than 20 warnings from US forces overnight as it tried to enter an Iranian port. The ship remained adrift in the Gulf of Oman and US forces have not boarded it.
With the latest action, the US military has stopped six ships trying to breach the blockade. One was allowed to proceed. Another 116 ships have been redirected.
The disabling of the Lian Star is the most dramatic single enforcement action taken since the blockade began on April 13 and provides a graphic illustration of the degree to which the US Navy and Air Force are actively enforcing what the United States has described as a complete embargo on maritime trade with Iran.
The Blockade: What It Is and How It Is Being Enforced
On April 13, 2026, the United States imposed a naval blockade on Iran following the failure of the Islamabad Talks to end the 2026 Iran war. The US military said the blockade had begun at 10 a.m. Eastern Time and would apply only to ships going to and from Iran.
The decision to impose the blockade came seven days after the April 8 ceasefire was agreed. It represented a significant escalation of economic pressure: the ceasefire had paused the air and missile campaign, but the naval blockade imposed a separate form of coercion, specifically targeting Iran’s ability to export oil and import goods.
Iran said it would view the entry of military vessels near the strait as a breach of the two-week ceasefire and would respond accordingly. The blockade has been one of the central points of contention in the subsequent ceasefire negotiations, with Iran demanding its lifting as a precondition for any meaningful progress on the Hormuz question.
In practical terms, the blockade has been enforced through a combination of US Navy surface vessels, maritime patrol aircraft, and carrier-based air assets operating in the Gulf of Oman and the approaches to Iranian ports. Ships attempting to reach Iran have been contacted by radio and visual signals, warned to turn around, and — when they have not complied — subjected to escalating responses.
The Lian Star: What Happened
The Lian Star is a Gambia-flagged bulk carrier — a type of commercial vessel typically used to transport grain, coal, or other dry bulk commodities. Its flag registration in Gambia places it formally under Gambian maritime jurisdiction, making its targeting by a US military asset a matter with international maritime law dimensions that will be examined carefully in the coming days.
The vessel made its approach to an Iranian port overnight, during the hours when the Gaza ceasefire with Lebanon was reported to be at a sensitive point in negotiations and when the broader Iran war diplomatic track was in its most intense phase yet.
The US Central Command said the Gambia-flagged cargo ship Lian Star ignored more than 20 warnings from US forces overnight as it tried to enter an Iranian port. The military fired a missile into its engine room.
The decision to fire a missile into the engine room — rather than placing warning shots across the bow or in the water adjacent to the vessel — represents a calibrated use of force designed to disable without sinking. An engine room strike removes a vessel’s propulsion without necessarily causing it to sink or endangering the crew beyond the immediate risk of the strike itself. US forces have not boarded the vessel, leaving its crew aboard a disabled ship in the Gulf of Oman.
The flag state of the vessel — Gambia — will be entitled under international maritime law to request consular access to the crew and to lodge a formal protest with the United States. The shipping company’s ownership and the vessel’s cargo and destination will also be subjects of investigation.
The Pattern of Blockade Enforcement
The Lian Star is the sixth vessel stopped since April 13, but the broader picture of the blockade’s impact is told by a different number: 116 ships redirected.
That figure describes the day-to-day enforcement reality of the blockade — the constant pressure of US naval and air assets maintaining a cordon around Iranian ports that requires any vessel approaching to make a choice: turn around, or risk being stopped. The overwhelming majority of vessels are choosing to turn around. The six that have been disabled or stopped represent the outliers who chose not to, whether out of financial calculation, political direction, or miscalculation.
The blockade has been estimated as costing Iran $500 million per day in lost revenues. That figure — if accurate — represents a financial haemorrhage that has accelerated Iran’s willingness to negotiate, even as it has also hardened Iranian public and political opinion against the US. The blockade is simultaneously the most effective piece of economic leverage the US holds in the negotiations and one of the most significant obstacles to a final settlement — because Iran has demanded its lifting as a core condition of any deal.
The International Maritime Law Dimension
The US naval blockade of Iran sits in contested territory under international law. A blockade is a recognised instrument of war under international humanitarian law — but its legal validity depends on the existence of a state of armed conflict and on the blockade being properly declared, notified, and enforced without causing disproportionate harm to neutral parties.
The US-Iran conflict, which began on February 28, provides the armed conflict context. The blockade was publicly declared and notified to the international maritime community. But questions remain about whether the enforcement of a blockade that affects civilian commercial shipping — vessels like the Lian Star carrying goods rather than weapons — is proportionate to the military objective.
Those questions have been raised by China, Russia, and several European governments, who have noted that the blockade’s impact extends well beyond its stated military rationale to encompass a form of collective economic punishment that affects not only Iran but the global trade networks that depend on access to the Persian Gulf.
A US official previously told the Associated Press that the US has not found or destroyed any mines in the strait. That admission is significant: one of the stated rationales for the blockade and for ongoing US strikes near the Hormuz approaches is the Iranian mine-laying threat. If mines are not being found, the operational justification for the blockade’s most aggressive enforcement measures becomes harder to sustain publicly.
The Negotiating Context
The disabling of the Lian Star happened on the same day as ongoing negotiations between US and Iranian officials over the memorandum of understanding that would extend the ceasefire and begin formal nuclear talks. The juxtaposition — firing missiles at commercial ships while simultaneously seeking a diplomatic resolution — is not accidental. It is the signature dynamic of this entire conflict: military pressure maintained and even intensified precisely to improve the US bargaining position at the negotiating table.
The memorandum of understanding makes clear that Iran will not be able to impose tolls on the Strait of Hormuz and that Iran will have to remove all mines from the vital waterway within 30 days. The blockade, under the emerging deal framework, would be lifted in exchange for Iran’s removal of mines and reopening of the strait. But the sequencing — who moves first, who verifies what — remains one of the hardest parts of the negotiation to resolve.
For the crew of the Lian Star, drifting disabled in the Gulf of Oman as diplomats negotiate in closed rooms, the sequencing is an abstraction. Their situation is immediate and unresolved.
What Happens Next
US forces have not boarded the Lian Star. The vessel’s crew is aboard. The question of what happens to the ship — whether US forces eventually board it, whether a tug is dispatched, whether the vessel drifts into Iranian-claimed waters — will play out over the coming hours and days.
At the broader level, the blockade enforcement pattern is expected to continue regardless of the state of negotiations. The US has consistently maintained that the blockade is a separate instrument from the ceasefire and that it will remain in place until a final agreement specifically addresses its lifting. That position keeps the economic pressure on Iran while talks proceed — but it also generates incidents like the Lian Star that complicate the diplomatic environment and provide Iran with ammunition for its argument that the US is conducting economic warfare while calling for peace.
LoudFact.com is an independent global news and explainer platform. This report is based on reporting from the Washington Post, PBS NewsHour, ABC News, Las Vegas Sun, the Washington Times, and the Associated Press as of May 30, 2026.
