The US Navy has demolished "small boats" of Houthi rebels attempting to board a container ship in the Red Sea.
Four vessels from Houthi-controlled areas in Yemen fired upon the Maersk Hangzhou and got to within metres of the ship, the US military said, reports BBC.
Helicopters from nearby US warships responded to a distress call and after being fired upon, sunk three of them "in self-defence".
The crews were killed and the fourth boat fled the area.
The Houthis have been attacking ships in the Red Sea since November.
The Iranian-backed Yemeni rebel group have claimed its attacks on the vital shipping lane are directed at vessels linked to Israel, in response to the war in Gaza.
The commercial ship attacked, the Maersk Hangzhou, is registered to Singapore and operated and owned by a Danish firm, US Central Command (Centcom) said.
Maersk, one of the largest shipping companies in the world, says it has paused sailings through the Red Sea for 48 hours.
The four Houthi boats attacked at around 06:30 Yemeni time (03:30 GMT) with mounted weapons and small arms, getting to within 20m (66ft) of the container ship, which the crew "attempted to board". The ships crew issued a distress call and a security team returned fire, the statement said.
Helicopters from the nearby USS Eisenhower aircraft carrier and USS Gravely destroyer responded to the call for help and were shot at while "in the process of issuing verbal calls to the small boats".
The helicopters "returned fire in self-defense, sinking three of the four small boats, and killing the crews", Centcom said. It added that the fourth boat "fled the area" and no damage had been recorded to US personnel or equipment.
It was the second attack on the Maersk Hangzhou in 24 hours, after it was attacked with missiles on Saturday.
Bd-pratidin English/Lutful Hoque
