The International Maritime Organization (IMO) suspended its large-scale evacuation of ships and crews from the Persian Gulf on Thursday, hours after a Singapore-flagged container vessel was hit by a projectile in the Gulf of Oman. IMO Secretary-General Arsenio Dominguez said the pause was necessary “to reconfirm that the necessary safety guarantees continue to be in place” for vessels on the evacuation list and all others in the region. The decision halted an operation launched only two days earlier that aimed to move hundreds of ships and some 11,000 seafarers stranded since the outbreak of US-Iran hostilities in late February.

US officials told multiple news organisations that Iran’s Islamic Revolutionary Guard Corps (IRGC) was responsible for the attack on the Ever Lovely, which sustained damage to its bridge but no casualties. The IMO noted that the vessel was not transiting under its evacuation framework. The strike came after the IRGC Navy broadcast warnings that the Strait of Hormuz was “closed” and that only routes designated by Iran would be permitted, describing a newly announced corridor along the Omani coast as “unacceptable and extremely dangerous.” Iran’s Persian Gulf Strait Authority separately stated that any passage outside its own framework would not be covered by safe-passage guarantees or insurance.

The incident and the IRGC’s warnings directly challenge the interim US-Iran memorandum of understanding signed the previous week, under which Tehran committed to facilitate toll-free safe passage for 60 days. Viewed from Washington, Secretary of State Marco Rubio, touring Gulf allies, said that if Iran threatened or blocked ships, “then we’re going to have a problem,” and reiterated that the strait is an international waterway where no country may levy fees. Oman, which jointly announced the temporary evacuation routes with the IMO, has said it does not intend to charge tolls, but Iranian officials have signalled they may impose maritime service fees after the 60-day period, a prospect the US has called unacceptable.

The evacuation pause leaves thousands of seafarers in limbo and injects fresh uncertainty into the fragile ceasefire. Maritime traffic through the strait had been gradually recovering, with 70 transits recorded on Wednesday—the highest since the war began—but still well below the pre-war daily average of 130. Oil prices edged up, with traders citing renewed uncertainty over the timeline for normalising Gulf energy flows. The IMO has not indicated when the evacuation might resume, stating only that it will seek further clarity on security guarantees. Diplomats in Muscat and European capitals are watching whether Iran and Oman can agree on joint management of the waterway, a key unresolved element of the 60-day negotiating window.