Iran's Islamic Revolutionary Guard Corps said on Thursday that only Tehran-approved routes were valid for commercial shipping through the Strait of Hormuz, defying an Omani-backed plan to establish a safe corridor.
The move puts the powerful military force at odds with Oman. It also indicates deepening divisions within Iran's post-war establishment.
The IRGC has emerged as the leading voice against concessions in talks with the US. Its unilateral assertion of control over routes appears designed to undercut any agreement that does not preserve Iranian leverage over the waterway.
The IRGC Navy's rejection came only a day after Oman and the International Maritime Organisation said they had secured the necessary guarantees to begin evacuating more than 11,000 stranded seafarers from the Gulf.
Oman portrayed the plan as having been developed “in line with outcomes and efforts reached by the United States and the Islamic Republic of Iran” – making the IRGC's opposition all the more striking.
“Safe passage through the Strait of Hormuz is only possible via routes announced by the Islamic Republic of Iran,” the IRGC Navy was quoted as saying by the Tasnim news agency. Co-ordination through the marine radio frequency VHF Channel 16 was mandatory, it added, warning that “action will be taken against violating vessels”.
The threat directly contradicts assurances given by IMO secretary general Arsenio Dominguez, who said the evacuation would be carried out in co-operation with Iran, Oman, other coastal states and the US.
“We remain fully committed to ensuring the safety of seafarers and the continuity of global trade,” he said.
The conflicting instructions create further uncertainty for the estimated 600 vessels considering ways to leave the Gulf safely.
Maritime officials have begun contacting trapped ships, instructing them to proceed to designated waiting areas before entering the strait in phased sequences. Vessels may choose either a northern route through Iranian waters or a southern route through parts co-ordinated by Oman and the US.
For the Oman-authorised eastbound corridor, ships had been told to contact radio station “A4N”, also on VHF Channel 16, before reaching the first waypoint. The two temporary routes were introduced after the central channel was considered unsafe, with reports of naval mines making it impassable.
An IMO spokeswoman stressed the humanitarian dimension of the operation. “They're not military, they're not trained for these things. They're seafarers from India, the Philippines – it's been quite a challenge,” she said.
Oman and Iran have also agreed to establish a joint working group to discuss the future management of navigation in the strait – an arrangement the IRGC's announcement now appears to complicate.
Hormuz traffic surge
Lloyd's List Intelligence said traceable traffic through the Strait of Hormuz surged 270 per cent to 119 transits last week after a memorandum of understanding between Washington and Tehran partially reopened the waterway. That figure is still far below the 700 recorded during the same period last year.
The increase masks a confused, two-tier system split between the Iran-controlled northern route and US-protected southern corridor. Security consultancy Marisks warned that while the immediate risk of an outright closure had “substantially” decreased, this should not be read as a return to unrestricted commercial navigation.
The IRGC has reportedly stopped issuing new transit permits for the northern corridor entirely, with only vessels already holding permission or directly selected by Iranian authorities being allowed to pass.
Dr Anwar Gargash, diplomatic adviser to President Sheikh Mohamed, warned that “new geopolitical facts cannot be imposed on the Arab Gulf states as a result of a treacherous aggression against them”. He was referring to Iranian attacks on the UAE and its neighbours during the conflict sparked by US-Israeli strikes on Iran between February 28 and an April 8 ceasefire.
“Imposing a fait accompli from the womb of aggression does not establish stability; rather, it sows new seeds of discord and conflict for the future,” he added.
Earlier this week, Oman and Iran had suggested they would impose costs for services provided to ships traversing the strait. The proposal drew an immediate riposte from Washington.
US President Donald Trump said tolls on vessels sailing through the Strait of Hormuz would be a red line in negotiations with Tehran. “It would be unacceptable for me,” he said.
While meeting Gulf officials in Manama on Thursday, US Secretary of State Marco Rubio rejected any attempt to impose charges on vessels using the waterway.
“The Strait of Hormuz is a waterway that no country owns,” he said. “No country has the right to impose transit fees."
He added that any agreement reached with Tehran would guarantee the interests of Washington's regional allies.
At the same meeting, Omani Foreign Minister Badr Al Busaidi said: "Future arrangements related to the strait do not entail the imposition of any transit fees." The comment posted on X did not refer to the service costs mentioned in the joint statement issued with Iran on Tuesday.
The Strait of Hormuz carries more than 20 per cent of the world's liquefied natural gas and crude oil, making any disruption a major concern for global energy markets.
