The credibility of the United States as a reliable security guarantor is increasingly being questioned, as the Houthi campaign against ships in the Red Sea continues, an American institute said.

CARE International, Oxfam and Save the Children called on the Houthi group to immediately and unconditionally release UN staff in the capital, Sana’a.

Missile and drone attacks by Iran-allied Houthi rebels in Yemen have halved commercial shipping in the Gulf of Aden and the Red Sea, with the top US naval commander in the region saying he sees little appetite among carriers to return in large numbers to the waterway. Despite the vital operation being protected by American forces and their allies.