Iran is suspected to have fired on a tanker crossing the Strait of Hormuz in a renewed burst of fighting over the critical waterway.
Tensions have risen since Tehran fired on a transiting cargo vessel two days ago. In response, the US launched fresh strikes inside Iran, prompting it to attack an American military base in Bahrain.
The tit-for-tat exchanges threaten to reverse the surge in traffic crossing the Strait that has followed the signing of an interim peace deal earlier this month.
United Kingdom Maritime Trade Operations (UKMTO), Britain’s maritime security agency, said a tanker was hit on Saturday but did not say who fired the projectile.
Iranian state television reported that the Revolutionary Guards had fired “warning shots” at ships crossing the waterway on channels not approved by the regime.
2706 Hormuz territorial waters
The US has encouraged tankers to sail close to Oman, but Tehran is ordering vessels to pass closer to its coast, where they can be made to pay fees.
The Islamic Republic is seeking to formalise its control of the 13-mile channel through which around a fifth of global oil supplies passed before the war began.
Drone and missile fire effectively prevented tankers exiting the Gulf during the three-and-a-half-month conflict.
A cargo vessel in the Strait of Hormuz, where the reopening of the waterway has been hit by delays and Iran has fired on ships – Elke Scholiers/Getty Images
Under the terms of the interim peace deal, Iran has 60 days to allow the resumption of toll-free traffic through the strait.
The agreement’s language is hazy on whether Tehran will be allowed to charge fees after the end of that period, with analysts speculating that negotiations could swing that way.
The Trump administration has offered as much as $300bn (£220bn) of funding if the Islamic Republic drops its nuclear ambitions and becomes a peaceable member of the international community.
But the Iranian attacks have pushed Washington to respond militarily once more. On Friday night, the US military hit missile, drone and radar sites along the coast.
Credit: U.S. Central Command
Donald Trump, the US president, said the Islamic Republic had “foolishly” violated the ceasefire by targeting a tanker.
JD Vance, the vice-president, wrote on X that Tehran should “pick up the phone” if they have “disagreements about how the MOU [Memorandum of Understanding] is being applied”.
Otherwise “violence will be met with violence,” he warned.
Bahrain said it had been hit by Iranian drones on Saturday, in what it described as a violation of the Memorandum of Understanding.
2606 More oil is getting out of the Gulf
Oil prices have tumbled back to pre-war levels since the lifting of Iran’s blockade of the Strait.
The number of tankers crossing the Strait had risen sharply before the resumption of fighting.
On Wednesday, 73 vessels made the journey, according to Kpler, a maritime analysis firm. Some 54 followed on Thursday.
But tanker operators may choose to keep their vessels away from the choke-point while the conditions for passage remain unclear and potentially dangerous.
Iran and the US have often engaged in bursts of fighting at the weekend, with hostilities typically resolved in time for the opening of the markets on Monday.