US President Donald Trump had earlier called the attack a violation of the Iran ceasefire.

American forces struck 10 Iranian targets after Washington said Tehran attacked the tanker Kiku with a drone in the Strait of Hormuz. The exchange has sharpened fears over ceasefire collapse, shipping security and the wider US-Iran deal.

IRGC says it targeted 'US terrorist army' in response to overnight strikes following Iranian attack on ship that tried to leave strait; Bahrain: Iran 'sabotaging peace efforts'

"Obviously, this is a foolish violation of our Ceasefire Agreement," said the US president, after the attack halted efforts to evacuate hundreds of ships and thousands of sailors stranded in the Gulf.

Iran launched missile and drone strikes on US military sites in Kuwait and Bahrain after fresh American attacks on Iranian targets. As tensions surged despite a fragile ceasefire, US President Donald Trump warned Iran could "cease to exist" if Washington is forced to escalate its military response.

Iran launched a drone assault targeting Bahrain while a ship in the Strait of Hormuz separately came under attack Saturday, likely Tehran’s response to overnight airstrikes by the United States.

The warring sides each accused the other of violating the agreement reached two weeks ago to end the four-month-old conflict.

The strikes mark the worst escalation since the US and Iran signed an interim peace deal two weeks ago.

The Singapore-registered cargo ship, operated by Taiwan's Evergreen Marine Corp, was hit by a projectile off the coast of Oman.