The Strait of Hormuz, one of the world’s most critical waterways for oil transport, remained almost completely blocked on Thursday despite a U.S.-Iran ceasefire. Ship traffic through the narrow passage fell to well below 10% of normal levels as Iran asserted control by ordering vessels to stay within its territorial waters.
Hundreds of tankers and other ships have been trapped inside the Persian Gulf since the Iran war began on February 28. The conflict has caused the largest oil supply disruption in history, cutting global supply by about 20%. On Thursday, physical oil prices hit fresh all-time highs as the crisis showed few signs of easing.
According to ship-tracking data from Kpler, Lloyd’s List Intelligence, and Signal Ocean, only seven ships passed through the strait in the past 24 hours. Normally, around 140 vessels transit the waterway each day. The handful of ships that did move included one oil products tanker and six dry bulk carriers. One chemical tanker was also preparing to cross toward India.
Iran’s Islamic Revolutionary Guard Corps (IRGC) issued new instructions through the semi-official Tasnim news agency. The IRGC told ships to sail close to the Iranian island of Larak to avoid naval mines supposedly present in the usual shipping lanes. Vessels must enter the strait north of Larak Island and exit just south of it until further notice, coordinating directly with the IRGC navy.
Maritime security experts warned that risks remain high. British firm Ambrey noted that ships not authorized by Iran—especially those linked to Israel or the United States—face particular danger. Even vessels that appear to have approval have been turned back mid-transit in recent weeks.
The IRGC also released a map guiding ships around the reported mine areas. Some media reports suggest Iran may try to charge a toll of up to $2 million per ship for passage. Ship-tracking data already shows a few vessels taking the unusual route around Larak Island. However, Western leaders have strongly opposed any such payments.
The United Nations’ shipping agency, the International Maritime Organization (IMO), stated there is no international agreement allowing tolls on vessels passing through international straits. An IMO spokesperson warned that introducing such fees would set a dangerous precedent.
One Indian-flagged LPG tanker, the Pine Gas, recently used the Larak route to exit the Gulf without paying any toll or being boarded by Iranian forces. Its chief officer, Sohan Lal, confirmed the details to Reuters.
Japan’s Mitsui O.S.K. Lines, one of the country’s largest shipping companies, successfully brought three tankers out of the strait in recent days. The company’s president and CEO, Jotaro Tamura, said they are now waiting for guidance from the Japanese government on how to operate during the two-week ceasefire.
India, facing its worst cooking gas crisis in decades, has introduced rationing for households. The government granted special waivers to allow two Iranian cargoes—one carrying liquefied petroleum gas (LPG)—to enter its ports aboard older or sanctioned tankers.
The United States issued a surprise waiver last month allowing Iranian oil exports, but that waiver is set to expire on April 19. Despite the disruptions, at least 23 Iranian-flagged tankers have still reached Asia since the war began on February 28, maintaining roughly the same pace as before the conflict, according to the U.S. advocacy group United Against Nuclear Iran (UANI).
Risk intelligence firm Verisk Maplecroft warned that most shipping companies will likely remain cautious. Even if traffic increases significantly, analysts say it will take far longer than two weeks to clear the massive backlog of vessels stuck in the Gulf.
The CEO of UAE state oil giant ADNOC called on Iran to reopen the strait immediately and without conditions. As of Thursday, however, the Hormuz Strait remained at a near standstill, with global energy markets continuing to feel the strain of the ongoing crisis.