Nigeria is preparing for nationwide elections that will be watched to see if officials can avoid a repeat of the chaos and fraud that marred the 2007 polls.
Voters will cast ballots on three consecutive Saturdays starting April 2 to elect members of parliament, a president and 36 state governors.
The head of the country's electoral commission, Attahiru Jega, has promised credible elections. However, violence in several parts of Nigeria has risen as the polls draw near, raising concerns that voting will be disrupted again.
European Union observers deemed the 2007 elections "not credible" - citing numerous reports of ballot box-stuffing, poor organization and election-day violence.
For this year's voting, the electoral commission has compiled a new voter list and put out detailed directions for election workers, with the stated goal of making the polls free and fair.
Nigeria, with about 140 million people, is Africa's most populous nation and a major oil producer.
President Goodluck Jonathan is seeking his first full term, after taking office last year upon the death of President Umaru Yar'Adua.
His run has generated controversy in the ruling People's Democratic Party, with some party leaders saying he broke an informal deal to rotate the party's presidential nomination between northern Muslims and southern Christians.
The late president Yar'Adua, a Muslim, died just three years into what was expected to be a two-term, eight-year presidency. Mr. Jonathan, a Christian, has been in office since last May.
The president is facing 19 challengers - including Nigeria's former military ruler Muhammadu Buhari. Opinion polls have shown Mr. Jonathan in the lead.
Some information for this report was provided by Reuters.