It was a rough start to an election with so much at stake: Nigeria needs to show it can make it through this vote fairly and peacefully to get its big economy humming and to press forward with tackling the Boko Haram Islamist militants.
But the technology that was supposed to make the election process easier is threatening to undermine it. Election officials said some polling stations would extend voting into Sunday after problems with hand-held devices used to verify voter identity.