MORE than 80 African migrants have been rescued from the Sahara desert after they were robbed and left to die by people they had paid to smuggle them to Libya, according to the U.N. migration agency, citing survivors. Drivers abandoned four trucks carrying the migrants from Nigeria, Togo, Mali and Ghana with no food or water about 230 km (143 miles) north of the Sahara crossroad town of Niger's Dirkou after spotting military vehicles. Three days later, an IOM rescue team found the group, which included children, by chance on Sept. 3. Many were dehydrated, injured and in need of…