IRGC Seizes Barbados-Flagged Tanker in Gulf of Oman as US Disables Iranian Ships

Iranian naval commandos boarded and seized the Barbados-flagged tanker Ocean Koi in the Gulf of Oman on Friday, guiding the vessel to Iran's southern coast and handing it to judicial authorities. Within hours, US Central Command said it had disabled two Iranian-flagged tankers trying to reach Iranian ports. The two operations, announced almost back to back on May 8, turned a war of statements over the Strait of Hormuz into a war of seized and crippled hulls.

Iran's account, carried by state news agency IRNA, said the Ocean Koi was captured because it was "attempting to disrupt oil exports and the interests of the Iranian nation" by "exploiting regional conditions." The Iranian Army said the boarding was carried out under a decision of the Supreme National Security Council. Video and reporting described domestic speedboats and armed personnel taking the ship, then walking it to port.

The ship at the center of it

The Ocean Koi is not a random target. Maritime tracking firm TankerTrackers says the vessel previously sailed as the Jin Li and moved Iranian hydrocarbons at least 16 times since 2021. The US Treasury's OFAC had placed it under sanctions in February 2026 as part of what Washington calls Iran's shadow fleet, the loose network of aging, often reflagged tankers used to move sanctioned crude and dodge tracking.

That history matters, because both sides are telling a story that fits their case. Tehran frames the Ocean Koi as a hostile actor working against Iranian exports. US officials frame the same ship as a sanctioned carrier of Iranian oil. A tanker built to move Iranian barrels quietly ended up as the trophy in a very public seizure. The registry helps explain the diplomatic reach of the incident: Barbados, a small flag state with no dog in this fight, now has one of its ships in Iranian custody.

What CENTCOM did

CENTCOM said its forces disabled two Iranian-flagged tankers as they tried to access Iranian ports in the Gulf of Oman. In at least one case, US forces disabled the rudder of the Iranian-flagged M/T Hasna after its crew allegedly ignored repeated warnings during an interception. Disabling a rudder, rather than sinking or boarding, is a deliberate choice. It leaves a ship dead in the water and unable to steer without putting a large crude carrier on the bottom of a crowded waterway.

Admiral Bradley Cooper, the CENTCOM commander, said US forces in the region "remain committed to full enforcement of the blockade." That word, blockade, is the tell. The US is no longer describing routine sanctions enforcement. It is describing a naval cordon meant to stop Iranian crude from moving at all, and it is willing to physically stop ships to make the point.

A blockade being tested in real time

The seizures did not happen in a vacuum. Reporting says that in the two days before Friday, three empty crude tankers belonging to Iran's National Iranian Tanker Company crossed the US Navy blockade line by hugging Pakistan's exclusive economic zone, using another country's waters as cover. Their combined capacity was around five million barrels. Empty tankers slipping through toward loading ports are exactly the kind of traffic a blockade is meant to stop, and their transit shows how porous the cordon still is.

The Friday actions came just hours after US and Iranian forces traded fire near the Strait of Hormuz, where, by Iran's account, its forces launched missiles and drones at three US warships and American forces struck Iranian launch sites in response. US officials said no American vessels were hit. Iran claimed 10 sailors wounded and five missing. Those casualty figures come from Tehran and have not been independently confirmed.

Toll booths on the Strait

The most consequential move may be the one that got the least airtime. Iran announced the creation of a "Persian Gulf Strait Authority," a body that would require ships transiting the Strait of Hormuz to obtain clearance and pay toll fees. Roughly a fifth of the world's oil moves through Hormuz. An Iranian permitting-and-toll regime, backed by the ability to seize a ship that does not comply, is an attempt to convert a chokepoint into a tollgate that Tehran controls.

Whether it holds is another question. A toll authority is only as real as the navy enforcing it, and the US blockade sits directly across the same water. What the announcement does is give Iran a legal-sounding framework for exactly the kind of seizure it carried out against the Ocean Koi. Comply and pay, or risk your ship. The Ocean Koi is the demonstration model.

What it means for the oil market

Prices are already carrying a war premium. Brent was trading around $100 a barrel and WTI near $94 as the news broke, well above where they sat before the fighting escalated. Traders are not pricing a clean supply cut so much as the risk that Hormuz stops functioning as a predictable passage. Polymarket data cited alongside the seizure put the odds of traffic returning to normal by the end of May at just 28 percent.

For owners and charterers, the calculus has changed fast. A blockade on one side and a seizure-backed toll authority on the other means every voyage through Hormuz now runs a gauntlet where either navy might stop your ship. War-risk insurance premiums move on days like this, and some owners will simply decline the transit. That is the real supply threat, not a single seized tanker but a chokepoint that shipping companies start avoiding.

The Ocean Koi is now Iranian evidence in an Iranian court, and the Hasna is drifting without a rudder somewhere in the Gulf of Oman. Neither ship matters much on its own. What matters is that two governments have decided the way to win the argument over Hormuz is to start taking each other's ships apart, and the fragile pause everyone kept invoking looks thinner than it did on Thursday.