Iran has warned that it will soon block what it describes as illegal routes through the Strait of Hormuz, raising fresh concerns about the movement of crude oil and petroleum products through one of the world’s most important energy shipping corridors.
Brigadier General Mohammad Reza Naqdi, a senior adviser to the commander-in-chief of Iran’s Islamic Revolutionary Guard Corps (IRGC), said the country’s armed forces would close a small number of passages allegedly created by vessels blasting through rocky sections of the strait.
According to Mehr News Agency, Naqdi said on Wednesday that Iran had full control of the waterway and would maintain its position until its demands were met. He also alleged that some operators were using small vessels to smuggle oil through the routes before transferring it to tankers.
Naqdi described the volume of oil moving through these passages as negligible, arguing that their use should not be interpreted as evidence that the Strait of Hormuz is fully open. He said Iranian authorities would soon block the routes.
The announcement introduces another uncertainty for shipowners, oil traders and exporters already navigating heightened security risks in the Gulf. Any additional restrictions on navigable passages could complicate vessel movements and increase operational uncertainty, although the actual effect will depend on which routes are closed and whether the measures affect established commercial shipping lanes.
The Strait of Hormuz is a critical export route for crude oil and petroleum products from Gulf producers. Prolonged restrictions or further disruption to tanker traffic could constrain the volume of oil reaching international markets, while increasing shipping delays, freight rates and insurance costs.
Iran’s warning also comes amid claims that Persian Gulf oil exports are recovering towards pre-war levels. However, renewed restrictions on maritime movements could undermine that recovery if they affect the passage of commercial tankers or discourage shipowners from operating in the area.
For oil markets, the key issue is whether Iran’s proposed action remains limited to the passages it has described as illegal or develops into wider restrictions affecting commercial shipping. A broader disruption could reinforce supply concerns and put upward pressure on crude prices, while limited enforcement against smuggling routes may have a more contained effect.
For Nigeria, sustained disruption around Hormuz could support international crude prices by increasing concerns over global supply. However, higher freight and insurance charges, alongside more expensive imported petroleum products, could raise costs across the downstream market. The net impact would depend on the scale and duration of the disruption, international price movements and Nigeria’s domestic supply conditions.
Iran has linked the status of the waterway to its wider dispute with Washington, including demands relating to US military action and the naval blockade. Until there is greater clarity over the security arrangements governing the strait, the outlook for Gulf oil shipments will remain exposed to geopolitical developments.