Four people are presumed dead and 11 others are still missing after a Liberian-flagged cargo ship sank in the Red Sea following an attack by Yemen's Houthi rebels, a European Union naval mission said Friday.

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.