Residents stand near a smouldering remains of a bus targeted in a suicide attack in the northeast Nigerian town of Potiskum, on February 24, 2015. Two blasts rocked bus stations in embattled northern Nigeria on February 24, killing at least 27 people, as relentless attacks persist less than five weeks from general elections. The first, killing 17, was caused by a bomb that ripped through a station on the outskirts of Potiskum, in northeast Yobe state, which has been targeted repeatedly by Boko Haram Islamists. AFP PHOTO / AMINU ABUBAKAR        (Photo credit should read AMINU ABUBAKAR/AFP/Getty Images)