DUBAI, United Arab Emirates (AP) — A Liberian-flagged cargo ship attacked by Yemen’s Houthi rebels sank Wednesday in the Red Sea, with a European naval force in the Mideast saying that only six of 25 people who were on board have been rescued.

The UN's Yemen envoy has expressed serious concern over the situation in the Red Sea, and warned of potential environmental damage after two Houthi attacks on commercial vessels. The incidents mark the first such attacks since Washington announced a truce with the Iran-backed rebel group in May.

Yemen's Iran-backed Houthi rebels claimed responsibility Wednesday for a deadly attack that sank a merchant vessel earlier this week, their second attack on Red Sea