Photo courtesy of Tasnim news agency.
The trading of fire, which came after Washington accused Tehran of attacking a cargo ship in the Strait of Hormuz earlier in the week, raised questions about efforts to keep the crucial waterway open while both sides negotiate a broader, final deal.
US Central Command (CENTCOM) said the latest American strikes, against Iranian missile and drone storage sites and coastal radar positions, were a response to "unwarranted aggression against commercial shipping by Iranian forces" that "clearly violated the ceasefire".
But Iran lashed out at the attacks after its Revolutionary Guards launched its own retaliatory strikes.
"These brutal attacks, which targeted Iranian coastal surveillance facilities, are a blatant violation" of the memorandum of understanding to end the war, the Iranian foreign ministry said.
The Guards said they had struck US sites in the Gulf region in retaliation and that "if the aggression is repeated, our response will be broader than this", according to a Telegram post by state TV.
Bahrain's foreign ministry said the country was targeted by several Iranian drones early Saturday, condemning the attacks and accusing Tehran of "sabotaging peace efforts".
On the US strikes, Iranian state television, citing a reporter in the southern city of Sirik, said an explosion was heard at a pier there late Friday. It quoted a military source saying a "projectile impact" in the area caused the blast.
"Sirik Port is operating normally, and no damage has been reported to its equipment or facilities," Mehr news agency later said.
CENTCOM described the operation as "a powerful response to yesterday's attack on a commercial ship that was transiting the Strait of Hormuz".
US President Donald Trump had earlier denounced what he described as an Iranian drone strike on the vessel, saying "this is a foolish violation of our ceasefire agreement".
Vice President JD Vance issued a direct warning, posting on X that "violence will be met with violence" if Iran carries out any further attacks.
Iran has warned vessels not to enter or leave the Gulf through the strait without permission, but ships have continued to move, some using a route not authorised by Tehran.
Despite the latest flare-up, oil prices have fallen sharply on hopes that traffic through Hormuz -- a strategic waterway which normally sees around a fifth of the world's oil and gas exports -- would keep recovering.
- Nuclear safeguards -
The UN nuclear watchdog has warned that any final US-Iran settlement would need strong safeguards to ensure Tehran does not build a nuclear weapon.
Iran's nuclear programme remains a central sticking point, with Tehran and Washington giving conflicting accounts of whether inspectors will regain access to the Islamic republic's facilities.
"The government of Iran has declared quite clearly that this is not their intention," International Atomic Energy Agency chief Rafael Grossi said Friday of developing nuclear weapons.
"But of course intentions are not enough. We have to have a very strong verification system in place... as soon as is practicable."
The interim agreement says Iran's stockpile of enriched uranium should be "downblended" under IAEA supervision.
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