The war erupted more than a month ago with US-Israeli strikes on Iran, triggering a retaliation that has spread the conflict throughout the Middle East and convulsed the global economy -- particularly due to the closure of the strait, a vital conduit for oil and gas.
"Remember when I gave Iran ten days to MAKE A DEAL or OPEN UP THE HORMUZ STRAIT," Trump wrote on Truth Social, referring to an ultimatum issued on 26 March.
"Time is running out -- 48 hours before all Hell will reign (sic) down on them."
Iran's central military command rejected the ultimatum, with General Ali Abdollahi Aliabadi saying Trump's threat was a "helpless, nervous, unbalanced and stupid action".
Echoing Trump's language, he warned that "the gates of hell will open for you".
Trump later posted a video showing explosions lighting up a night sky along with text that said: "Many of Iran's Military Leaders...are terminated, along with much else, with this massive strike in Tehran", without specifying when it took place.
Search for airman
Tehran said Friday it had shot down an F-15 warplane and US media reported United States special forces had rescued one of its two crew members, with the other still missing.
Iran's military also said it downed a US A-10 ground attack aircraft in the Gulf, with US media saying the pilot of that plane was rescued.
The local Mehr news agency on Saturday quoted the deputy governor of Kohgiluyeh and Boyer-Ahmad province, Fattah Mohammadi, as saying the search for the missing airman involved "popular forces and tribesmen alongside military forces and is still ongoing".
He added that "last night, people fired at enemy helicopters with rifles and did not allow them to land".
Images posted on social media and verified by AFPTV showed Iranian police firing at a US helicopter in southwestern Iran as US forces searched for the airman.
Bushehr nuclear plant
A strike near Iran's Bushehr nuclear plant on Saturday killed a guard and led Russia, which partly constructed the facility and helps operate it, to announce it was evacuating 198 workers and to condemn the strike as "an evil deed".
Iranian Foreign Minister Abbas Araghchi warned that continued attacks on the plant on the southern coast could eventually lead to radioactive fallout that would "end life in GCC (Gulf Cooperation Council) capitals, not Tehran".
Bushehr is considerably closer to Kuwait, Bahrain and Qatar than it is to the Iranian capital.
Rafael Grossi, head of the International Atomic Energy Agency wrote on X that no increase in radiation levels had been reported at the site, but nonetheless voiced "deep concern" at what he said was the fourth such strike in recent weeks.
There were also more strikes on Tehran, where an AFP journalist saw a thick haze of smoke covering the skyline.
Economic sites hit
Strikes by all sides have increasingly targeted economic and industrial sites, raising fears of wider disruption to global energy supplies.
US-Israeli strikes on Saturday hit a petrochemicals hub, a cement plant and a trade terminal on the Iran-Iraq border, where one person was reported killed.
Iran has retaliated with missile and drone attacks on Israel and US allies in the Gulf.
Shrapnel from intercepted drones injured four people in Bahrain on Saturday, and two buildings in Dubai were hit by debris, including one housing the US cloud computing firm Oracle, authorities said.
On another front, the Israeli military said Friday it had struck more than 3,500 targets across Lebanon in the month since the latest round of fighting with Iran-backed Hezbollah began.
As night fell Saturday, Israel warned it would strike near a border crossing between Syria and Lebanon, ordering residents to evacuate.
In Tel Aviv, hundreds of Israelis marched to protest the war and demand peace talks.
