Yemeni fighters from the Houthi movement said they will close Saudi Arabia’s coast starting Monday. Their spokesman, Yahya Saree, called it a naval attack. Merchant ships moving through the Red Sea near Saudi ports could face delays. U.S. warplanes kept hitting targets after their warning. The group took several ships. Insurers now see Red Sea routes as risky. Traders are watching closely, watching for extra costs or alternative loads. Saudi ports are close to the risk area, so any carries swift impact.