(Reuters) – The Saudi-led military coalition fighting against Yemen’s Houthi movement reopened a land border crossing, partly easing a blockade imposed earlier this week, but aid agencies warned of famine and a health catastrophe if other ports stay shut. The coalition said on Monday it would close all air, land and sea ports in Yemen to stem the flow of arms to the Houthis from Iran, after Saudi Arabia intercepted a missile fired towards its capital Riyadh.