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.

Houthi rebels in Yemen attempted to strike Israel’s Ben Gurion airport after sinking two vessels in the Red Sea this week, as the group ramps up its military pressure in support of Palestinians under Israeli fire in its bid to bring the war in Gaza to an end.

A Houthi attack on the Greek ship Eternity C on Wednesday killed four of the 25 people aboard, maritime officials said. On Thursday, rescuers pulled four more survivors from the Red Sea. Houthi militants said they were holding some of the crew still missing.