GENEVA The UN refugee agency, UNHCR, on Friday called for urgent international support to tackle the worsening displacement crisis in Africa's Sahel region, where about 4 million people are now uprooted across Burkina Faso, Mali, Niger, and neighboring countries. The figure is around two-thirds more than five years ago, according to the agency. "The region cannot face these challenges alone," Abdouraouf Gnon-Konde, UNHCR's regional director for West and Central Africa, told reporters in Geneva,