An oil tanker was struck by an unidentified projectile while transiting the Strait of Hormuz off the coast of Oman on Monday, causing a fire on board but no casualties or environmental damage, according to the United Kingdom Maritime Trade Operations (UKMTO). The vessel was hit on its port side approximately eight nautical miles east of Limah, Oman, as it travelled southbound towards the Gulf of Oman. The UKMTO advised all ships in the area to exercise caution and report suspicious activity, adding that authorities are investigating the incident.

US officials, cited by the Axios news website, accused Iran of launching at least two missiles at commercial vessels in the strait on Monday night, including the damaged tanker. The reported attacks came after a one-week suspension of hostilities between Washington and Tehran expired, and the US is now said to be considering retaliatory strikes against Iranian targets. Iranian state television, Irib, quoted anonymous sources confirming that the tanker was attacked by Iran after it ignored repeated warnings not to use a southern route through Omani waters. However, no Iranian authority has officially confirmed or denied this account, and Tehran has not formally claimed responsibility.

The incident threatens to unravel a fragile ceasefire and a memorandum of understanding signed last month between the United States and Iran, which aimed to end the conflict that began on 28 February and to reopen the strategic waterway. While maritime traffic has resumed, Iran insists there will be no return to pre-war arrangements under which vessels could pass freely. Tehran has warned ships to use only a corridor it has authorised along its coastline and has threatened a “forceful response” against those that do not comply. The Strait of Hormuz remains the primary maritime gateway for Gulf energy exports, with around 20 million barrels of crude oil passing through daily in 2024, roughly one-fifth of global supply, according to the US Energy Information Administration.

Indirect talks in Doha last week between US and Iranian diplomats ended without a breakthrough on the future of commercial shipping through the strait. Viewed from Washington, the latest strike is likely to harden the administration’s stance and complicate ongoing diplomatic efforts. In Tehran, the incident coincided with the funeral procession of Supreme Leader Ali Khamenei, who was killed along with four family members in the opening day of the war, drawing millions of mourners into the streets. The UKMTO investigation is ongoing, and no group has yet claimed responsibility. The US Central Command has reiterated its commitment to the free flow of commerce through the strait, while regional states have underscored the same principle in recent meetings.