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.

The search operation for missing crew members of the ship Eternity C, which was sunk by Yemen's Houthi rebels in the Red Sea, has officially ended. At least four people are now presumed dead, while 11 others remain unaccounted for,