Tanker strike in Hormuz raises pressure on US-Iran ceasefire

A tanker was damaged in the Strait of Hormuz on Saturday (27 June) after being hit by a projectile, Britain’s maritime security agency said, as fresh US and Iranian strikes marked the sharpest escalation since the two sides signed an interim peace deal.

Britain’s UKMTO said the vessel’s bridge had been damaged, but all crew were reported safe. The Joint Maritime Information Centre, run by a coalition of navies protecting commercial shipping, raised its security threat level after a series of recent incidents in the waterway.

The tanker incident followed an attack on a cargo ship on Thursday, which helped trigger the latest round of violence. Iran has made a renewed push to assert control over the Strait of Hormuz, the world’s most important energy shipping route, which had started to reopen after months of disruption.

Washington and Tehran each accused the other of breaching the agreement reached two weeks earlier to end the four-month-old conflict. The US said it struck Iranian targets overnight, while Iran said it answered on Saturday with attacks on targets linked to US forces.

Iran has not directly addressed the reported attacks on individual ships. Iranian state television said the Revolutionary Guards had fired “warning shots” towards unspecified vessels trying to use routes not approved by Iran, and said other ships were now seeking Iranian permits before crossing the strait.

Iran’s foreign ministry described its attacks on US-linked military targets as “defensive”. Bahrain, which hosts the US Navy’s regional headquarters, reported an Iranian drone attack. The US military did not immediately respond to the reports.

Tehran has also accused Washington of failing to uphold the interim agreement, particularly by not sustaining a promised ceasefire in Lebanon. Israel, a US ally, invaded Lebanon in March in pursuit of Hezbollah, the Iran-backed militant group.

Israel and Lebanon have repeatedly agreed to US-brokered ceasefires, the latest of which was announced on Friday. But the deals have had limited overall effect, with Israel insisting it will not withdraw from territory it has seized, while Hezbollah has rejected calls to disarm as long as Israeli troops remain.

Lebanese state television reported an Israeli drone strike on Saturday in the southern Nabatiyeh area, which has seen Israeli attacks throughout the conflict. The Israeli military said it had targeted a person who posed a threat to its forces.

Hezbollah leader Naim Qassem rejected the day-old Israel-Lebanon agreement as a surrender and said it was “null and void”. Anger over the deal has spread beyond Hezbollah into the wider Shi’ite community, with hundreds of thousands of Lebanese, mainly Shi’ite Muslims, still unable to return to homes in Israeli-occupied areas.

Israeli Defence Minister Israel Katz welcomed the agreement, saying it allowed Israel to maintain its occupation of a so-called security zone in Lebanon and barred displaced residents from returning.

Mohsen Rezaei, an adviser to Iran’s supreme leader, said Washington had violated the war-ending memorandum of understanding by supporting what he called “proxy forces” in the region and by creating tensions in the Strait of Hormuz.

Throughout the war, Iran has responded to US attacks by striking neighbouring Gulf states that host major US military bases. Iranian state television said the Revolutionary Guards had delivered “a decisive response” after US forces struck a communications tower in the Iranian port city of Sirik. Iran’s Mehr news agency said the port was operating normally and that no damage had been reported to facilities or equipment.

Bahrain said Iran’s latest attacks violated the memorandum of understanding.

Hundreds of ships, including oil-laden tankers, have been blockaded inside the Gulf since the war began. As vessels started leaving through the strait over the past two weeks, oil prices fell close to pre-war levels because of the resulting increase in supply.

A full resolution would require sustained two-way traffic through the Strait of Hormuz at pre-war levels, which is likely only if shippers regard the route as safe. Washington has promoted a southern lane along the coast of Oman, while Tehran, which ultimately wants to charge fees for use of the strait, wants vessels to take a northern route through Iranian waters and under Iranian control.

Ebrahim Azizi, head of the Iranian parliament’s national security committee, said on Saturday that any breach of Iran’s shipping instructions would be met decisively.

US Vice President JD Vance, President Donald Trump’s chief negotiator on the conflict, said Washington had adhered to the ceasefire deal and blamed Iran for any renewed conflict caused by its actions.

“Iran signed a ceasefire agreement. We have honoured it. If they have disagreements about how the MOU is being applied, they can pick up the phone. But violence will be met with violence,” Vance said on X.

The escalation unfolded over the weekend while markets were closed, giving both sides two days to take hard positions and exchange fire without causing an immediate impact on oil prices.

Over the previous two weekends, tough rhetoric on Friday and Saturday was followed by more conciliatory positions from both sides before markets reopened on Monday.

Before the renewed violence, oil prices had fallen about 3% on Friday and were on course for a steep weekly decline.

Reuters