TOPSHOTS A young Nigerian throws water on a campaign poster of Nigeria's main opposition All Progressives Congress (APC) presidential candidate Mohammadu Buhari as youth try to remove it from the vicinity of polling booths where Buhari will cast his vote in line with electoral law at Sarki Yara A, Waziri Road, Daura in Katsina State on March 27, 2015. Nigeria is due to vote on March 28 for a new president, in the most closely fought election since independence, framed by Boko Haram violence, economic woes and endemic corruption. AFP PHOTO/PIUS UTOMI EKPEI