Nigeria’s newly elected president, Muhammadu Buhari, is vowing to make every effort to free hundreds of girls abducted by Boko Haram militants. <br /><br /> A year after they were taken from a boarding school in Chibok, campaigners are taking to the streets to pile pressure on the government.<br /><br /> “When your voice is taken, you can’t speak. You don’t exist. But our girls exist,” said campaigner Oby Ezekwesili, as she taped over her mouth.<br /><br /> Almost 300 schoolgirls were abducted last April. Dozens escaped, but 219 remain missing.<br /><br /> Led by Abubakar Shekau, Boko Haram is trying to establish an Islamic caliphate. <br /><br /> With help from Nigeria’s neighbours,Niger, Cameroon and Chad, the militants have been forced to retreat from an area the size of Belgium in recent weeks. <br /><br /> Euronews reporter Luis Carballo has been embedded with troops fighting Boko Haram on the frontline. <br /><br /> “The joint operation, particularly Chad’s involvement, is starting to change things on the ground,” said Carballo.<br /><br /> Euronews was wi
