Riyadh is balancing pressure on the Houthis with efforts to keep Iran from widening the conflict, as attacks threaten Saudi energy exports through the Red Sea.

The Iranian-backed Houthis launched an offensive to take areas bordering the Red Sea, prompting heavy clashes and exchanges of fire with Saudi-backed government forces.

The World Health Organization said Monday that at least 728 people have been killed or wounded in Yemen since Aug. 24.