By Renee Maltezou and Jonathan Saul ATHENS/LONDON (Reuters) -Rescuers pulled three more crew members and a security guard alive from the Red Sea on Thursday, maritime security sources said, a day after Houthi militants sank the Greek ship Eternity C and said they were holding some of the crew still missing.

In just days, Yemen's Houthi rebels have begun a new, more violent campaign of attacks targeting ships in the Red Sea, sinking two of them and killing some of their crew.