An attack by Yemen's Houthi rebels on a Liberian-flagged cargo ship in the Red Sea killed three mariners and wounded two others, a European Union naval force said Tuesday, highlighting the danger of the group's renewed campaign targeting a key maritime route for international trade.

A Liberian-flagged cargo ship came under fire on Monday in the Red Sea, with two security guards on board reportedly hurt and two others missing in an assault that came after Yemen's Houthi rebels purportedly sunk another vessel in a similar attack.

A Liberian-flagged cargo ship attacked by Yemen’s Houthi rebels sank Wednesday in the Red Sea, and a European naval force in the Mideast said only six of the 25 people who were on board have been rescued.