World·UpdatedA tanker reported being struck by a projectile in the Strait of Hormuz on Saturday, Britain's maritime security agency said, after the United States and Iran each launched strikes in the worst escalation since they signed their interim peace deal.U.S. and Iran engage in tit-for-tat strikes, the worst since signing interim peace dealThomson Reuters · Posted: Jun 27, 2026 8:25 AM EDT | Last Updated: 1 minute agoListen to this articleEstimated 5 minutesThe audio version of this article is generated by AI-based technology. Mispronunciations can occur. We are working with our partners to continually review and improve the results.Oil tanker Al Shaffiah sails at sea near the Omani coast, as seen from Musandam, Oman, on Friday. (Stringer/Reuters)A tanker reported being struck by a projectile in the Strait of Hormuz on Saturday, Britain's maritime security agency said, after the United States and Iran each launched strikes in the worst escalation since they signed their interim peace deal.The warring sides each accused the other of violating the agreement they reached 10 days ago to end the four-month-old conflict. Washington said it hit Iranian targets overnight, while Iran said it had struck targets linked to U.S. forces on Saturday in response.Saturday's attack on a tanker in the strait followed an attack on a cargo ship on Thursday that triggered the escalation. Iran has made a fresh bid to assert control over the world's most important energy shipping route, which has begun to reopen after months of disruption.Britain's UKMTO maritime security agency said the tanker that was hit on Saturday had sustained damage to its bridge, with all crew reported safe. The Joint Maritime Information Center, run by a coalition of navies protecting shipping, said it had raised its security threat level as a result of recent incidents.Iran has not directly commented on reports of specific attacks on ships.U.S. strikes Iran in retaliation for attack on cargo ship in Strait of HormuzBut Iranian state television reported that the Islamic Revolutionary Guard Corps had fired "warning shots" toward unspecified ships attempting to pass through channels not approved by Iran and that this was now prompting other ships to seek Iranian permits before attempting to cross the strait.Earlier, Iran's Foreign Affairs Ministry said it had launched "defensive" attacks on U.S.-linked military targets while Bahrain, which hosts the U.S. navy's regional headquarters, reported an Iranian drone attack. The U.S. military did not immediately respond to the reports.Iran asserts control over vital straitIran has accused the United States of failing to uphold the interim agreement, in particular by failing to sustain a promised ceasefire in Lebanon, which U.S. ally Israel invaded in March in pursuit of the Iran-backed militant group Hezbollah.Israel and Lebanon have repeatedly agreed to U.S.-brokered ceasefire deals, the latest of which was announced on Friday. But these have so far had only limited overall impact, with Israel insisting it will not withdraw from a swath of territory it has seized, and Hezbollah repeatedly rejecting calls to give up its arms as long as Israeli troops remain in place.Lebanese state television reported an Israeli drone strike on Saturday in the Nabatieh area in the south, which has seen Israeli strikes throughout the conflict.WATCH | Latest developments between U.S. and Iran:U.S. strikes Iran in response to drone attack that violated ceasefire: Trump | Hanomansing TonightJune 26|Duration 4:40The fragile ceasefire between the U.S. and Iran hangs in the balance after U.S. President Donald Trump accused Iran of attacking a cargo ship in the Strait of Hormuz.Mohsen Rezaei, an adviser to Iran's supreme leader, said the U.S. had violated the war-ending memorandum of understanding by supporting what he called proxy forces in the region and creating tensions in the Strait of Hormuz.Throughout the war, Iran has responded to U.S. attacks by hitting neighbouring Gulf states that host large U.S. military bases.Iranian state television said the Revolutionary Guards had delivered "a decisive response" after U.S. forces hit a communications tower in the port city of Sirik. Iran's Mehr News Agency said the Iranian port was operating normally with no damage reported to facilities or equipment.Bahrain said Iran's latest attacks violated the memorandum of understanding.Israel, Lebanon sign framework agreement with U.S. in 'first step' toward peaceHundreds of ships, including tankers laden with oil, have been blockaded inside the Gulf since the war broke out. As they began leaving through the strait over the past two weeks, oil prices have tumbled close to pre-war levels on the resulting surge in supply.But fully resolving the global energy crisis would require sustaining two-way traffic through the strait at pre-war levels, likely to be possible only if shippers come to accept it as safe.Washington has been promoting a southern lane along the coast of Oman, while Tehran, which ultimately aims to charge fees for use of the strait, wants ships to use a northern route through its waters and under its control.Ebrahim Azizi, head of the Iranian parliament's national security committee, said on Saturday that any violation of Iran's shipping instructions would be met decisively.'Violence will be met with violence': VanceU.S. Vice-President JD Vance, President Donald Trump's chief negotiator on the conflict, said the Americans had adhered to the ceasefire deal and that Iran was to blame for any return to conflict that might result from 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 social media platform X.As has regularly been the case throughout the war, the escalation unfolded over the weekend while markets were closed, giving the sides two days to stake out tough positions and exchange fire without causing any immediate surge in oil prices.In past cases, including both of the last two weekends, bitter words on Friday and Saturday were followed by more ameliorative positions from both sides in time for markets to reopen on Monday.Before the renewed outbreak of violence, oil prices fell about three per cent on Friday, on course for a steep weekly fall.