Iran Closes Hormuz Strait After Tanker Attack

Iran said it will keep the Strait of Hormuz closed after reversing an earlier move to reopen the waterway and after an incident in which a tanker attempting to transit was fired upon on Saturday, April 18, 2026. Tehran linked its position directly to U.S. policy, saying the closure would remain in place as long as the U.S. blockade of Iranian ports continues.

Iran’s joint military command said control of the Strait of Hormuz had returned to what it described as its previous status, under strict military management. In the same period, two Iranian Revolutionary Guard gunboats reportedly opened fire on a tanker in the Strait. The British military’s United Kingdom Maritime Trade Operations center reported that the vessel and its crew were safe.

Shipping disruption was also reported beyond the single incident. TankerTrackers.com said other vessels were forced to turn back, underscoring the operational impact of the closure on commercial traffic. The Strait of Hormuz is widely viewed as a critical maritime chokepoint for energy flows, and the reported turn-backs highlight how quickly security developments can translate into logistical constraints.

The escalation followed a statement from U.S. President Donald Trump that the blockade on Iranian ports would remain in effect until a deal is reached that addresses Iran’s nuclear program. Iran’s decision to maintain the closure was presented as a response to that position, tying maritime access to the continuation of the blockade.

The Strait of Hormuz carries approximately one-fifth of the world’s oil supply, making it central to global energy trade and pricing. Any sustained interruption to passage through the Strait can heighten uncertainty for oil markets and for countries and companies dependent on seaborne crude and refined product shipments. S. and Iran, given the direct linkage both sides have drawn between the blockade, nuclear talks, and maritime access.

S. and Iran appear to be nearing a deal ahead of an April 22 ceasefire deadline. That deadline also coincided with a 10-day truce between Israel and Hezbollah that was reported to have largely held. Key uncertainties include how long Iran will sustain the closure, whether additional commercial vessels will be turned back, and whether diplomatic efforts referenced by Pakistani officials will change the immediate security posture in and around the Strait.