Iran reopened the Strait of Hormuz on Friday during a ceasefire in the Middle East war, only to close it again hours later on Saturday and fire on commercial ships attempting passage, according to maritime tracking data and security monitors.¹²³

At least eight oil and gas tankers passed through the strait early Saturday morning following Iran's Friday afternoon announcement, according to data from tracking firm Kpler.¹ The vessels included one crude oil tanker, four liquefied petroleum gas ships, two oil and chemical tankers, and one oil products vessel.¹ Marine Traffic data showed several other crude tankers near Iran's Larak Island, a control point for ships attempting to exit the Gulf during the Iranian blockade.¹

Iran's central military command announced Saturday morning that control over the strait had "returned to its previous status" and was now under "strict management and control" in response to a continuing US naval blockade of Iranian ports.² The reversal came after US President Donald Trump insisted the American fleet blockade would continue until a peace agreement was reached, despite his earlier statement that a deal to end the US-Israel war with Iran was "very close".²

Members of Iran's Revolutionary Guard (IRGC) fired on a tanker in the strait and threatened to "destroy" an empty cruise ship attempting to flee the Gulf, according to the UK Maritime Trade Operations agency and security firm Vanguard Tech.³ The UKMTO said in an online statement that the IRGC fired on the tanker northeast of Oman, though the crew and vessel remained safe.³ Vanguard identified the vessel as the Indian-flagged tanker Sanmar Herald, reporting that two IRGC patrol boats approached without radio contact and "shots were fired causing damage to the bridge windows".³

The strait normally carries approximately one-fifth of the world's oil and liquefied natural gas, but traffic through the route had nearly stopped after war broke out on 28 February with American and Israeli attacks on Iran.¹ Data showed very few ships were still attempting to use the waterway by Saturday afternoon, with several vessels that had been en route turning back quickly.³