Hundreds of African migrants were stranded in dire conditions in a desert area of southern Tunisia on Thursday after being expelled from the port city of Sfax, witnesses told AFP. Racial tensions flared this week into violence targeting migrants from sub-Saharan African countries, with dozens fleeing the city or being forcibly evicted.NGOs say hundreds of migrants have been taken in buses to desert areas in southern Tunisia, some near the border with Libya and others close to the frontier with A