Oman

Iranian commander says US military attacked two passenger boats, not IRGC vessels, in the Strait of Hormuz on Monday.

Iran has accused the United States of killing five civilians in the Strait of Hormuz, saying its forces attacked passenger vessels in the waterway rather than boats belonging to the Islamic Revolutionary Guard Corps (IRGC) as claimed.

The claim on Tuesday contradicted a statement by US Admiral Brad Cooper, who said Central Command forces had sunk six IRGC vessels that had attempted to interfere with a US mission to escort stranded ships out of the Strait of Hormuz.

US President Donald Trump later put the number at seven boats.

The US operation, dubbed “Project Freedom”, has shaken a fragile ceasefire reached between Iran and the US on April 8 and renewed fears of a return to war.

Iran’s state broadcaster IRIB quoted an unnamed Iranian military commander as saying that Tehran launched an investigation following the US claim of attacks on IRGC vessels.

It said while none of the IRGC vessels was hit, the investigation found that US forces had “attacked two small boats carrying people on their way from Khasab on the coast of Oman to the coast of Iran on Monday”.

The attacks destroyed the boats and killed five civilian passengers, the commander said. The US “must be held accountable for their crime”, the commander added.

There was no immediate comment from the US military.

The violence comes as Trump seeks to reopen the Strait of Hormuz, which Iran has effectively blockaded following the US and Israeli attacks on the country on February 28.

The closure of the vital maritime corridor – through which roughly one-fifth of the world’s energy supplies flow – has sent oil and fertiliser prices surging around the world and prompted fears of a global recession and food emergency.

Iran is now insisting on maintaining control over the Strait of Hormuz and collecting transit fees as reparations for the destruction caused by the US and Israel.

Attacks on UAE, ships in Hormuz

The Iranian military on Monday warned commercial vessels they would “jeopardise their safety” if they attempted to cross the waterway without permission. The military also warned US forces would face attacks if they approached or entered the chokepoint.

Amid the tensions, the United Arab Emirates said Iran launched a drone attack on one of its oil tankers that attempted to transit the strait and said Iranian forces launched 15 ballistic missiles and four drones at its territory.

UAE authorities said the attacks set off a large fire at a major oil refinery in the eastern emirate of Fujairah and wounded three Indian nationals.

A South Korean vessel in the Strait of Hormuz, the HMM Namu, also reported an attack, saying an explosion had caused a fire in its engine room.

Nonetheless, the US military said two US-flagged ships made it through the strait on Monday with the support of navy guided-missile destroyers.

The IRGC denied the claim as “baseless and completely false”, but the global shipping firm Maersk said the US-flagged Alliance Fairfax exited the Gulf via the Strait of Hormuz accompanied by the US military on Monday.

Iran’s Foreign Minister Abbas Araghchi said the events in Hormuz on Monday “make clear there’s no military solution to a political crisis”.

He said in a post on X that peace talks with the US were “making progress” with Pakistan’s mediation and that Washington “should be wary of being dragged back into quagmire by ill-wishers”.

“So should the UAE,” he added. “Project Freedom is Project Deadlock.”

Meanwhile, Trump has renewed his threats against Iran.

He told Fox News Iran would be “blown off the face of the Earth” if they attacked US vessels carrying out Project Freedom.

“We have more weapons and ammunition at a much higher grade than we had before,” he said.

“We have the best equipment. We have stuff all over the world. We have these bases worldwide. They’re all stocked up with equipment. We can use all of that stuff, and we will, if we need it.”

On March 11, the Thai cargo ship Mayuree Naree was struck by two projectiles while crossing the Strait of Hormuz, one of the world’s most important waterways located between Iran and Oman. A fire broke out in the engine room, and while 20 sailors were rescued, three remained trapped inside the stricken vessel. Their remains were found weeks later when a specialised rescue team boarded the vessel, which had run aground on the shores of Iran’s Qeshm island.

At about the same time, a “shadow fleet” of tankers continued to navigate the very same waters safely. Operating with fake flags, disabled signals and unspecified destinations, this covert armada survived because it operates outside the traditional rules of maritime trade.

Iran threatened to block “enemy” ships passing through the Strait of Hormuz – a crucial chokepoint for a fifth of the world’s oil – in the wake of the United States-Israeli war launched on February 28. Soon, navigation through the strait was disrupted amid fears of attacks.

Following a temporary ceasefire on April 8, the United States imposed a full naval blockade on Iranian ports on April 13. Theoretically, traffic through the strait should have come to a complete halt.

However, tracking data reveals a remarkably different reality.

An exclusive Al Jazeera open-source investigation tracked 202 voyages made by 185 vessels through the strait between March 1 and April 15, navigating both under fire and across blockade lines.

The numbers behind the shadows

To understand how the strait operated under extreme pressure, Al Jazeera’s Digital Investigative Unit monitored the waterway daily, cross-referencing vessel International Maritime Organization (IMO) numbers with international sanction lists from the US Office of Foreign Assets Control (OFAC), the European Union, the United Kingdom and the United Nations. An IMO number is a unique seven-digit figure assigned to commercial ships.

Of the tracked voyages, 77 (38.5 percent) were directly or indirectly linked to Iran. Notably, 61 of the ships transiting the strait were explicitly listed on international sanctions lists.

The investigation divided the conflict into three distinct phases to map the fleet’s behaviour:

• Phase 1: Open War (March 1 – April 6): 126 ships crossed the strait, peaking at 30 vessels on March 1. Among these, 46 were linked to Iran.
• Phase 2: The Truce (April 7 – 13): 49 ships crossed during this fragile pause. More than 40 percent of these vessels were tied to Iran, including the US-sanctioned, Iranian-flagged Roshak, which successfully exited the Gulf.
• Phase 3: The US Blockade (April 13 – 15): Despite the explicit naval blockade, 25 ships crossed the strait.

Breaking the blockade

When the US blockade took effect, the shadow fleet adapted immediately.

The Iranian cargo ship “13448” successfully broke the blockade. Because it is a smaller vessel operating in coastal waters, it lacks an official IMO number, allowing it to evade traditional sanction-monitoring tools. The vessel departed Iran’s Al Hamriya port and reached Karachi, Pakistan.

Similarly, the Panama-flagged Manali broke the blockade, crossing on April 14 and penetrating the cordon again on April 17 en route to Mumbai, India.

The investigation uncovered widespread manipulation of Automatic Identification System (AIS) trackers. Vessels such as the US-sanctioned Flora, Genoa and Skywave deliberately disabled or jammed their signals to hide their identities and destinations.

Fake flags and shell companies

To obscure ultimate ownership, the shadow fleet heavily relies on a complex web of “false flags” and shell companies. The investigation identified 16 ships operating under fake flags, including registries from landlocked nations like Botswana and San Marino, as well as others from Madagascar, Guinea, Haiti and Comoros.

The operational network managing these ships spans the globe. Operating firms were primarily based in Iran (15.7 percent), China (13 percent), Greece (more than 11 percent) and the United Arab Emirates (9.7 percent). Notably, the operators of nearly 19 percent of the observed vessels remain unknown.

The toll of a parallel system

Despite the intense military pressure, energy carriers dominated the traffic, with 68 ships (36.2 percent) transporting crude oil, petroleum products and gas. Ten of these tankers were directly linked to Iran. Non-oil trade also persisted, with 57 bulk and general cargo ships crossing during the open war phase, 41 of which were tied to Tehran.

Before the war, at least 100 ships crossed the Strait of Hormuz daily. Today, a staggering 20,000 sailors are trapped on 2,000 ships across the Gulf – a crisis the International Maritime Organization described as unprecedented since World War II.

A shadow Iranian fleet, meanwhile, has been navigating seamlessly as part of a parallel maritime system born from 47 years of US sanctions on Tehran. Washington slapped sanctions on Tehran following the 1979 Islamic revolution that toppled the pro-Washington ruler Shah Mohammad Reza Pahlavi. The two countries have had no diplomatic ties since 1980.

The US naval blockade of Iranian ports and the Strait of Hormuz, in place since April 13, has raised concerns that Iran could run out of crude oil storage capacity and be forced to curb production.

Bloomberg reported analysis on Tuesday from the data and analytics company Kpler suggesting Iran could run out of crude storage in 12 to 22 days if the blockade persists.

Last week, United States Treasury Secretary Scott Bessent claimed that storage capacity at Kharg Island, where most of Iran’s oil is exported, would be full “in a matter of days”.

So how quickly could Iran run out of oil storage, and why does it matter?

What is happening in the Strait of Hormuz?

The Strait of Hormuz is a narrow channel that connects the Gulf to the open ocean. It spans the territorial waters of Iran on its northern side and Oman on its southern side. It is not in international waters.

During peacetime, 20 percent of the world’s oil and liquefied natural gas (LNG) supplies are shipped through the corridor.

Two days after the US and Israel launched their first air strikes in their war on Iran on February 28, Ebrahim Jabari, a senior adviser to the commander in chief of Iran’s Islamic Revolutionary Guard Corps (IRGC), announced that the strait was “closed”. If any vessels tried to pass through, he said, the IRGC and the navy would “set those ships ablaze”.

As the war has dragged on and negotiations have failed to achieve a settlement, Iran has at times in the past two months allowed some “friendly” ships and those that pay tolls to pass. It is currently refusing to allow any foreign-flagged ships, including those previously deemed friendly, to pass until the US lifts its own naval blockade.

Iranian First Vice President Mohammad Reza Aref said on April 19 that the “security of the Strait of Hormuz is not free”.

“One cannot restrict Iran’s oil exports while expecting free security for others,” he wrote in a post on X.

“The choice is clear: either a free oil market for all, or the risk of significant costs for everyone,” he added. “Stability in global fuel prices depends on a guaranteed and lasting end to the economic and military pressure against Iran and its allies.”

Since the US naval blockade on the strait began, the US has opened fire on and taken control of an Iranian-flagged tanker near the Strait of Hormuz while also redirecting vessels on the high seas transporting cargo to or from Iran. Iran’s armed forces have denounced these actions as “an illegal act” that “amounts to piracy”.

The US naval blockade of the strait means that Iran might have to store the oil it produces.

Iran is the third largest oil producer in the Organization of the Petroleum Exporting Countries (OPEC) after Saudi Arabia and Iraq and exports 90 percent of its crude oil via Kharg Island in the Gulf for shipping through the Strait of Hormuz.

What has the US claimed?

The US is eager to curb Iran’s oil revenues, which have risen since Tehran closed the Strait of Hormuz to other shipping. This is the primary motive behind Washington’s naval blockade of Iranian ports.

Iran exported 1.84 million barrels per day (bpd) of crude oil in March and shipped 1.71 million bpd in April, compared with an average of 1.68 million bpd in 2025, according to Kpler.

However, the US naval blockade since mid-April now means that most of its exports are having to be stored instead.

Bessent wrote in an X post on April 22: “In a matter of days, Kharg Island storage will be full and the fragile Iranian oil wells will be shut in.”

“Constraining Iran’s maritime trade directly targets the regime’s primary revenue lifelines.”

How much oil can Iran store?

Iran’s domestic refineries have a production capacity of 2.6 million bpd, according to the energy consultancy Facts Global Energy.

Satellite data show the amount of oil Iran has in storage has risen sharply since the US blockade began, and in the days after the US tightened it, stocks were rising so fast that it appeared Iran had been barely able to export any oil at all.

From April 13 to April 21, data showed that stocks rose by more than 6 million barrels, according to the Columbia Center on Global Energy Policy (CGEP). From April 17 to April 21, the stock increased very rapidly, growing by 1.7 bpd.

As of April 20, the storage tanks at Kharg were about 74 percent full after the island alone had taken on about 3 million extra barrels of oil, the CGEP reported.

Generally, oil companies avoid filling their storage beyond 80 percent capacity to balance safety, emissions control and flexibility.

However, Iran and other oil producing countries have exceeded this limit before, for instance, during the COVID-19 pandemic. In April 2020, Kharg island’s stocks reached close to 90 percent capacity, an all-time high.

Iran also has some crude oil storage capacity in the form of “floating tanks”, or parked ships. About 127 million barrels can be stored in this way, Frederic Schneider, a nonresident senior fellow at the Middle East Council on Global Affairs, told Al Jazeera in an interview on April 14.

Will Iran need to cut oil production?

Muyu Xu, a senior crude oil analyst at Kpler, told Al Jazeera that the blockade could eventually force Iran to cut production.

“However, given there is still available storage capacity onshore (roughly covering 20 days of Iran’s current production), we expect any production reduction to be gradual over the coming week with a higher likelihood of acceleration into May,” she said.

Analysis by CGEP nonresident fellow Antoine Halff echoed this. Halff wrote in an article published by CGEP on Tuesday that it may be some time before the US blockade causes Iran to shut off its production “in a big way”.

However, Halff added, Iran may still choose to halt production “fairly aggressively” but this “would be more by choice than by necessity”.

He explained: “Doing so would have the advantage of providing Iran with relatively ample spare storage capacity after the shutdown and would allow for a smoother restart of operations once conditions permit, and the constraint is relaxed, thus minimising adverse impacts from the blockade on longer-term supply.”

Why does this matter?

Halting oil production risks damaging underground reservoirs by reducing reservoir pressure, allowing water or gas to encroach into producing layers and changing patterns of oil flow. This can make some oil harder or more expensive to recover later, experts said.

Restarting the process of oil production can also be slow and costly, involving repairs of corroded equipment or unclogging pipelines.

Halting production would also cause Iran’s export revenues to drop. However, analysts said that for a few months, Iran can continue to earn revenue from oil that is already in transit at sea.

Kenneth Katzman, former Iran analyst at the Congressional Research Service in Washington, DC, said Iran is not exporting new oil during the US blockade of Iranian ports but Tehran has 160 million to 170 million barrels of oil on ships around the world currently.

The IRGC says the aggression came in response to what it described as the US seizure of an Iranian commercial vessel.

An Iranian gunboat has fired on a container vessel near the coast of Oman, according to a British maritime monitoring agency, in an incident that occurred hours after United States President Donald Trump said he would extend a ceasefire with Iran.

The United Kingdom Maritime Trade Operations (UKMTO) centre said on Wednesday that the ship’s captain reported that the vessel had been approached by a vessel of Iran’s Islamic Revolutionary Guard Corps (IRGC) before shots were fired.

It “has caused heavy damage to the bridge. No fires or environmental impact reported,” the agency added. No casualties were reported, and all crew members were said to be safe.

British maritime security firm Vanguard Tech said the ship was sailing under a Liberian flag and had been informed it had permission to pass through the Strait of Hormuz, one of the world’s most strategically important waterways.

Iranian news agency Tasnim, however, said the vessel had ignored warnings issued by Iran’s armed forces.

The incident followed a warning from the IRGC’s Khatam al-Anbiya Central Headquarters after what it described as the US seizure of an Iranian commercial ship in the Sea of Oman, the IRNA news agency reported.

It accused Washington of violating the ceasefire and carrying out “armed piracy” after allegedly firing on the Iranian vessel and disabling its navigation systems.

Trump extends ceasefire

Trump earlier announced he would delay a planned military attack on Iran after requests from Pakistan’s army chief Asim Munir and Prime Minister Shehbaz Sharif.

Writing on Truth Social, Trump said the decision was made because Iran’s government was “seriously fractured” and needed time to present a unified position.

“We have been asked to hold our Attack on the Country of Iran until such time as their leaders and representatives can come up with a unified proposal,” he wrote.

He added, however, that the US naval blockade of the Strait of Hormuz would remain in place and said the military had been ordered to stay “ready and able”.

The announcement marked a shift from comments made a day earlier, when Trump said it was “highly unlikely” he would extend the truce beyond Tuesday.

‘Positive and negative signals’ from Tehran

Al Jazeera’s Tohid Asadi, reporting from Tehran, said Iranian officials were sending mixed messages over the ceasefire and the prospects for negotiations.

“Tehran is saying they won’t negotiate under imposed terms and conditions … when we compare the initial 10-point and 15-point proposals by the Iranians and Americans, we can understand that the two sides are poles apart,” he said.

“The atmosphere is also clouded by this mistrust in Tehran towards the United States, as well as the simultaneous military rhetoric related to a potential failed negotiation … It is a warning that another round of confrontation may be ahead.”

He said Iran still viewed the Strait of Hormuz as a key source of leverage in any talks.

“It’s trying to exercise authority over the ships and vessels transiting this strategically significant chokepoint,” he said.

Asadi added that Iranian officials framed their regional position as based on mutual security. “Iranians are saying that the basis of their foreign policy behaviour, particularly when it comes to Israel, is security for all versus security for none,” he said.