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 search for those missing after Yemen's Houthi rebels sank a ship in the Red Sea has ended as at least four people are presumed dead and 11 others remain unaccounted for, the private security firms involved said Monday.

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