Nigeria's presidential and parliamentary elections have been delayed for a week.
The Independent National Electoral Commission (INEC) made the announcement just five hours before the polls were due to open on Saturday.
The vote has been rescheduled for Saturday 23 February.
The announcement came after an emergency meeting at the INEC headquarters in the capital, Abuja.
There are 73 registered candidates in the presidential election, but campaigning has been dominated by President Muhammadu Buhari, 76, and his main challenger, former Vice-President Atiku Abubakar, 72.
Mr Buhari says he has built a strong foundation for prosperity, but his rival says Nigeria is not functioning.