Six merchant vessels complied with direction from US forces to turn around to re-enter an Iranian port on the Gulf of Oman

The U.S. military said it will begin stopping all ships from leaving or entering Iran's ports in line with a blockade ordered by President Donald Trump.

CENTCOM has warned that blockade would apply to all ships regardless of flag

Six merchant vessels complied with direction from US forces to turn around to re-enter an Iranian port on the Gulf of Oman

US Central Command say more than 10,000 armed forces members, as well as warships and planes, are involved in blockade.

Analysts say that Iran has already moved vast quantities of its oil offshore and a full blockade would be complex to implement

The U.S. has signaled optimism about the prospect of reaching a diplomatic end to the Iran war.

At least four vessels tracked from Iranian ports appear to have crossed a US blockade line in the Gulf of Oman, analysis of ship-tracking data suggests.