One 34-year-old survivor from Senegal said he was taken to a dusty lot in the south Libyan city of Sabha after crossing the desert from Niger in a bus organised by people smugglers. The group had paid to be taken to the coast, where they planned to risk a boat trip to Europe, but their driver suddenly said middlemen had not passed on his fees and put his passengers up for sale.The men on the pick-up were brought to a square, or parking lot, where a kind of slave trade was happening. There were locals he described them as Arabs buying sub-Saharan migrants,