Nigeria elige presidente

El país mas poblado de Africa va a elecciones

Un modelo para Africa

Allegations of ballot-stuffing plagued the 2007 election, which brought Mr Jonathan to power as the vice-president.

He took over as president in 2010 when the incumbent died, becoming the first leader from the oil-producing Niger Delta region.

Although he enjoys huge popularity in the south of the country, he is sometimes characterised as a technocrat lacking in charisma.

His other main challengers for the presidency are former anti-corruption chief Nuhu Ribadu and Kano state governor Ibrahim Shekarau, though both are seen as rank outsiders.

Mr Jonathan's People's Democratic Party lost seats in a parliamentary election last week.

But he remains favourite in opinion polls, and his chances have been boosted after Mr Buhari and Mr Ribadu failed to agree a formal alliance to run against him.

The relatively successful conduct of the parliamentary election has increased confidence in the ability of the electoral commission, Inec, to ensure a fair presidential vote.

However, bomb blasts and other attacks killed dozens in the run-up to the polls.

With 74 million registered voters, Nigeria has the biggest electorate on the continent.

The head of the African Union's observer mission, former Ghanaian President John Kufuor, said some shortcomings had been found with the election process but he was confident the electoral commission would resolve them.

"If Nigeria gets it right, it will impact positively on the rest of the continent and show the rest of the world that Africa is capable of managing its electoral processes," said Mr Kufuor.

"If Nigeria gets it wrong, it will have a negative influence on the continent with dire consequences."