"Today, US Central Command Forces shot down four Iranian one-way attack drones that posed a threat around the Strait of Hormuz," the official, speaking on condition of anonymity, said in a statement to AFP.

"US forces also struck an Iranian ground control station in Bandar Abbas that was about to launch a fifth drone," the official said.

The new strikes come just days after the US military attacked several missile sites and mine-laying boats in the same area, in what US officials described at the time as taken in "self-defense."

Those strikes were seen as a significant test of the US-Iran ceasefire, but did not ultimately precipitate in a large-scale return to fighting.

The US official on Wednesday described the latest actions as "measured, purely defensive, and intended to maintain the ceasefire."