SANAA, Yemen — One million people across three Yemeni cities are at risk of a renewed cholera outbreak and other water-borne diseases following the closing of airports and sea ports by a Saudi-led coalition fighting Yemen’s Shiite rebels, an international aid group said Friday. The International Committee of the Red Cross said that the cities of Hodeida, Saada and Taiz were not able to provide clean water in recent days because of a lack of fuel. “Close to 1 million people are now deprived of clean water and sanitation in crowded urban environments in a country slowly emerging from the worst cholera outbreak in modern times,” said Alexander Faite, head of the Red Cross delegation in the war-ravaged nation. The Red Cross said other major urban cities, including the capital, Sanaa, will find themselves in the same situation in less than two weeks unless imports of essential goods resume immediately. The U.S.-backed coalition imposed a land, sea and air blockade on Nov.