Houthi rebels in Yemen have launched a violent new wave of attacks on ships in the Red Sea, sinking two vessels and killing crew members.

Yemen's Houthi rebels killed 3 mariners with an attack on a ship in the Red Sea, a European naval force says, fueling concern over a possible new wave of attacks by the Iran-backed group.

The attack on the Eternity C, which killed at least three of the crew, represents the most serious assault carried out by the Houthis in the crucial maritime trade route.