Iran's Islamic Revolutionary Guard Corps (IRGC) said it had attacked targets in the US-allied Gulf states of Kuwait and Bahrain.
In a statement carried by its Sepah News Telegram channel, the IRGC said its navy and air force had jointly launched missile and drone strikes in the early hours of Sunday, destroying eight key US military infrastructure targets in the two countries.
The claims could not initially be independently verified. There was no immediate response from the United States.
According to the statement, the targets included the US Air Force's Ali Al Salem Air Base in Kuwait and the headquarters of the US Fifth Fleet in Mina Salman, Bahrain.
The IRGC said the attacks were in response to what it described as the latest US aggression. It accused Washington of violating the framework agreement with Tehran aimed at ending the conflict, as well as the current ceasefire.
The agreement included arrangements with Iran governing shipping through the Strait of Hormuz, the IRGC said, warning that vessels violating those arrangements would now be targeted with greater severity than before.
The IRGC also warned that any aggression by its enemies would be met with a devastating response and said any breach of the ceasefire would bring the entire process to an end.
Earlier, the US military said it had carried out another retaliatory strike against Iran. It was the second US attack on Iran since the signing of a framework agreement between the two countries earlier this month.
On Friday, the United States said it had carried out airstrikes on Iranian missile and drone storage facilities as well as coastal radar sites in response to a drone attack on a commercial vessel in the Strait of Hormuz on Thursday that Washington blamed on Tehran.
