Key global oil and gas chokepoint shut as Iran turns back ships and bans traffic linked to US and Israeli allies, triggering worldwide market shock.

Iran’s Islamic Revolutionary Guard Corps (IRGC) has formally declared the Strait of Hormuz closed, issuing a stark warning that any vessel attempting to pass through the strategic waterway will face “harsh measures.”

In a statement released Friday via its Sepah News outlet, the IRGC said its naval forces had already enforced the directive by turning back three container ships of different nationalities earlier in the day. The vessels, according to the statement, attempted to transit the strait after what Iran described as “misleading claims” that the route remained open.

The Guard Corps further escalated tensions by announcing that all maritime traffic linked to allies of the United States and Israel is now explicitly barred from the passage.

The move marks a dramatic escalation in regional tensions, transforming long-standing threats into direct action at one of the world’s most critical energy corridors. The Strait of Hormuz handles roughly 20 percent of global oil supply and about 40 percent of internationally traded liquefied natural gas, making any disruption immediately consequential for global energy markets.

Shipping operators are now scrambling to reassess routes and risk exposure, while governments heavily dependent on Gulf exports face mounting uncertainty. Energy markets are already reacting, with analysts warning of potential supply shocks and price volatility if the closure is sustained.

The development follows weeks of rising friction in the region, including reports of vessels seeking costly assurances for safe passage and discussions of international naval escort arrangements that have yet to fully materialize.

With the IRGC now enforcing its position on the water, the situation has shifted from rhetoric to reality—placing one of the world’s most vital maritime lifelines at the center of a rapidly intensifying geopolitical crisis.