A mother sits under a makeshift tent with her children at a registration centre in Geidam stadium, Nigeria May 6, 2015. Niger has evacuated Nigerians living around Lake Chad, military and aid officials told Reuters on Tuesday, as the armies of four west African nations battle to quash the Islamist militants. A six-year insurgency by Boko Haram in Nigeria has seen thousands killed and displaced about 1.5 million people in the country. Nigerians who fled to the Nigerian border said they had been called out of their homes, lined up and brutally hurried out with no supplies. Some were picked up in trucks at the border town of Mainé-Soroa and taken to two camps in Geidam in Nigeria's Yobe state, set up in a primary school and a small stadium. Others walked the whole way or got rides for part of the way. Picture taken May 6, 2015. REUTERS/Afolabi Sotunde?