Fresh explosions have been reported in southern Iran, according to Iranian media.
Three explosions were heard east of the city of Bandar Abbas on the Strait of Hormuz, the Iranian news agency Fars reported early on Thursday.
The cause was initially unclear, as was the exact location of the incidents, the report said, adding that air defences had been activated.
Bandar Abbas is the capital of Hormozgan province and is considered one of Iran's most important military centres in the Gulf region.
Iranian media had only recently reported explosions in the area following overnight exchanges of fire with the US military.
The United States had attacked targets including sites on the Iranian mainland, while Iran had attacked US military vessels with missiles and speedboats. It remained unclear which side opened fire first.
