The latest round of attacks, which the United States said was launched in response to Tuesday's assault on three cargo ships transiting the strait, rattled several cities along Iran's southern coast and left some areas without power.
US President Donald Trump posted on Truth Social that strikes on Iran were retribution for attacks on ships, and if there are more "it will get
much worse!"
The US military's Middle East command said it had started conducting additional strikes against Iran "to further degrade their ability to threaten freedom of navigation in the Strait of Hormuz".
"The United States is holding Iran accountable for recent unjustified aggression against commercial shipping and civilian crews freely navigating a vital international waterway," CENTCOM said in a post on social media platform X.
Control of the strait, through which a fifth of global oil supplies pass, has given Tehran immense leverage, effectively allowing it to force a stalemate with the world's most powerful military.
While Iran has not claimed responsibility for the ship attacks, analysts say Tehran uses such actions to create leverage as it negotiates a long-term deal with the US.
The latest escalation dented hopes of turning a memorandum of understanding signed on June 17 into a permanent peace deal to end the war, which began with US-Israeli airstrikes on Iran on February 28.
Iran said on Wednesday it had attacked US military sites in Bahrain and Kuwait in response to earlier American strikes on a variety of military sites and port facilities.
Asked before a NATO summit in Turkey whether the memorandum of understanding was over, Trump said: "It's a very interesting question. To me, I think it's over. I don't want to deal with them.
"If we make a deal with Iran I'm not sure that will stick," Trump later said.
"I found them to be very dishonourable people."
Trump accused the country of launching drones and a missile at ships. "They are behaving very badly," he said.
But Trump, who has repeatedly threatened to escalate military action before backing off, said he did not expect a return to full-fledged war, and it was not clear whether the negotiations on reaching a permanent deal would continue.
"Anything that happens is going to happen very fast," Trump said, though he also suggested the US military might "just finish the job".
Iran's state news agency reported sounds of explosions in several areas on Iran's southern coast on the Gulf, including at the port of Bandar Abbas, and in the cities of Chabahar and Konarak, and that electricity had been cut off in parts of Chabahar.
Explosions were also reported in Sirik, another southern coastal city, and Bushehr, home to Iran's nuclear power plant complex.
On Wednesday, Iranian state television said eight members of the army's air and naval forces were killed in Bandar Abbas and Bushehr.
Nournews, affiliated with Iran's top security body, cited an Iranian military source as saying that Iran was planning to soon launch a "massive attack" on US army bases in the region in retaliation.
with AP
