The US military says one of its helicopters has fired missiles to disable "the steering gear" of a cargo ship attempting to violate the US blockade of Iranian ports.

In a statement, US Central Command (Centcom) says its MH-60 aircraft on Tuesday fired two hellfire missiles into the engine room of the Panama-flagged M/V Vela Nova vessel, as it attempted to transit the Gulf of Oman.

Centcom said it acted after "the ship's civilian crew ignored repeated warnings from American forces". The vessel "is no longer transiting to Iran", it added.

Iran has not commented. The US has been enforcing a blockade of Iranian ports, following failed attempts to end the war it and Israel started on 28 February.

Tehran retaliated by launching attacks on Israel and US-allied states across the Gulf. It has also effectively closed the Strait of Hormuz - a key oil shipping waterway.

A fifth of the world's oil and liquefied natural gas used to transit the strait before the war and prices have fluctuated wildly since then.

Mediators have so far failed to bring the sides to an agreement on reopening the strait - and, since the latest ceasefire collapsed in June, both the US and Iran have exchanged fire intermittently.

In its statement on X, Centcom said M/V Vela attempted to sail to an Iranian port without naming it. It also did not say whether there were any casualties or injuries.

It says the US blockade "remains in full effect", adding that as of 11 August Centcom has "redirected 55 commercial vessels attempting to run the blockade, disabled 3 non-compliant vessels, and boarded 2".

In a separate development on Tuesday, Yemen's internationally recognised government said six people were killed and 10 injured in strikes by Yemen's Iran-backed Houthis on a cargo ship in the Red Sea.

The Houthis said they hit a vessel carrying Saudi military equipment. It appears to be the first deadly attack by the group on a ship since the war began.