Iran has stopped two vessels attempting to exit the Strait of Hormuz, a direct challenge to the free flow of global energy supplies that has sent oil prices higher.
The incident marks a sharp reversal from the easing tensions that characterized the corridor earlier in the month, when diplomatic talks between the United States and Iran had begun to lower the risk premium embedded in crude benchmarks.
Brent crude futures rose in Friday trading as traders reassessed the security of the chokepoint, which handles roughly a fifth of the world's oil supply.
The halt of commercial traffic underscores the fragility of the interim peace deal and suggests that military posturing in the region remains a potent driver of energy market volatility.
This development follows a drone attack on ships in the Mediterranean, further highlighting the broadening scope of maritime security risks.
The incident complicates the narrative of steady normalization in Gulf shipping flows.