The strikes were the latest in a cycle of attacks and counter-attacks as Iran seeks to assert control over shipping through the strait. However, the barrage marked an escalation in pace and range.
The strikes extended to Qatar, a mediator in ceasefire talks that had not come under attack since April, while the United Arab Emirates, which had not been targeted since early May, said its air defences had engaged missiles and drones from Iran.
The US military began launching more strikes against Iran at 5pm on Sunday, US Central Command said in a statement on the social media platform X, "to continue degrading their ability to attack civilian mariners and commercial ships freely transiting the Strait of Hormuz".
In a phone interview with Reuters, US President Donald Trump referred to the weekend's strikes on Iran.
"We're beating them up," he said.
Iranian media said there had been missile attacks and explosions around the port of Bandar Abbas, home to military facilities on the strait, and nearby Qeshm Island.
The renewed violence casts further doubt on the future of an interim US-Iranian agreement signed last month that aimed to reopen the strait and end the war after a further 60 days of negotiations.
The war that the US and Israel launched against Iran on February 28 has destabilised the Gulf, where Iran has struck countries hosting US bases. Iran's effective blockade of the strait has driven energy prices higher, fuelling global inflation.
Higher prices, especially for gasoline, are politically sensitive for Trump ahead of November's congressional elections.
Iran has sought to establish a permanent system for collecting fees in the strait, which carried one-fifth of the world's oil and liquefied natural gas shipments before the war, and has warned vessels not to sail without its authorisation.
It said it had closed the waterway after firing a warning shot that struck a vessel travelling on an unauthorised route. On Sunday, it said it had disabled a second vessel.
India said one of its nationals was missing after an attack on the container ship GFS Galaxy off the coast of Oman. Oman said 23 crew members had been rescued. Qatar advised all vessels, including leisure boats, fishing boats and jet skis, to suspend activities.
Iran's recently created Persian Gulf Strait Authority said on Sunday that passage through the strait was not currently possible due to "recent illegal movements of the US military forces in the region".
The US, which revoked the licence authorising the sale of Iranian crude on Tuesday following earlier attacks on shipping, said its forces were positioned to safeguard freedom of navigation despite what it described as "aggression, harassment, threats, and arbitrary declarations" from Iran.
"Iran does not control the strait. Traffic is flowing," it said.
The US Navy-led Joint Maritime Information Center reiterated guidance that, despite a severe security threat, an "expanded" southern route near Oman was available for two-way traffic.
On Saturday, US Central Command said US forces had hit 140 Iranian military targets, and that more than 300 had been struck over three nights this week.
Iranian state media reported explosions in several port cities and said an Iranian army officer had been killed.
In response, Iran's Revolutionary Guards said they had destroyed a command-and-control centre and drone hangars in US ally Jordan, targeted a US radar site and later rocket launcher systems in Kuwait, attacked US aircraft carrier support and refuelling platforms in Oman and destroyed a jet maintenance centre and command facility in Qatar.
"A return to full-scale hostilities would have catastrophic consequences," United Nations Secretary-General António Guterres said in a statement.
Qatar, which has previously said it would not act as a mediator so long as it was under attack, said three people, including a child, had been injured by falling shrapnel. It said Iran was "fully legally responsible" for the attack.
The UAE said it detected missile threats outside its borders, while Bahrain said it intercepted several Iranian aerial attacks, Jordan reported missile strikes and Oman reported being targeted with drones. Kuwait's army later reported damage from strikes, and said an attack on an oil drilling platform injured a worker.
Iran's top negotiator, Mohammad Baqer Qalibaf, posted on X on Sunday: "The era of one-sided deals is OVER. We told you: keep your word or pay the price. Reality is knocking."
with AP
