Rescuers pulled six crew members alive from the Red Sea after Houthi militants attacked and sank a second ship this week, while the fate of another 15 was unknown after the Iran-aligned group said they held some of the seafarers.

Six crew members have been recovered and at least three others killed after a cargo ship was attacked by Yemen's Houthis and sank in the Red Sea, a European naval mission says.The Liberian-flagged, Greek-operated Eternity C was carrying 25 crew when it sustained significant damage and lost all propulsion after being hit by rocket-propelled grenades fired from small boats on Monday,

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