The US described the attacks as self-defense and said they were directed at targets around the Strait of Hormuz.
"The targets included missile bases and Iranian ships attempting to lay mines," Centcom spokesman Timothy Hawkins said in a statement to the television channel.
The Revolutionary Guard in Iran said on Monday that explosions were heard around the port city of Bandar Abbas and that air defenses had been activated to "combat hostile targets."
The US and Iran have also previously attacked each other during the ongoing ceasefire. Earlier in May, the US targeted Iranian military facilities in connection with Iranian missile and drone attacks on US warships.
US President Donald Trump claimed over the weekend that the two countries are close to reaching an agreement.
