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ABUJA - Nigeria's ruling party candidate Umaru Yar'Adua has been declared winner of a presidential poll rejected by the opposition and condemned by observers as a "charade".
Saturday's vote should lead to the first handover of power from one civilian leader to another in Africa's most populous nation and top oil producer. But observers and opposition groups said it was manipulated through violence and rigging.
Electoral commission head Maurice Iwu declared Yar'Adua of the People's Democratic Party (PDP) the winner with 24.6 million votes, far ahead of his closest rival, former army strongman Muhammadu Buhari, with 6.6 million.
Buhari rejected the result as "blatantly rigged" and called on parliament to impeach President Olusegun Obasanjo.
Thousands of opposition youths started street fires in the northern city of Kano but the protest was quelled by police and reaction elsewhere was muted.
World oil prices rose sharply on Monday because of fears of further violence in the world's eighth largest oil exporter, where militant attacks have already curbed output.
Nigeria, scarred by decades of corrupt dictatorship and military rule since independence from Britain in 1960, returned to civilian government in 1999.
Yar'Adua said he was "greatly humbled and challenged" and would reach out to the opposition. "I intend to invite them to join hands with me to work for this country," he said.
Allegations of rigging were not based on fact, he added.
European Union observers cited poor election organisation, lack of transparency, significant evidence of fraud, voter disenfranchisement, violence and bias.
"These elections have not lived up to the hopes and expectations of the Nigerian people and the process cannot be considered to have been credible," said chief EU observer Max van den Berg.
The United States said the vote was "flawed" but stopped short of calling for it to be overturned. Problems should be resolved peacefully and according to the constitution, State Department spokesman Sean McCormack said.
A coalition of civil society observers called for the vote to be cancelled and held again.
"The election was a charade. A democratic arrangement founded on such fraud can have no legitimacy," it said in a statement.
But any annulment would plunge Nigeria into a constitutional crisis because by law Obasanjo must hand over power on May 29.
Obasanjo said the election could not be described as perfect but appealed to aggrieved losers to use the courts for any complaints over the next five weeks.
"Nothing should be done to make our people lose faith in the electoral process and its democratic outcome," he said.
Analysts had predicted Yar'Adua would win because of the ruling party's unrivalled funds and powers of incumbency, but Buhari had been expected to put in a much stronger showing because of widespread disaffection with poverty and crime.
About 65 people have been killed in the past 10 days in election-related crime. Four people were killed in armed clashes between criminal gangs in the southern oil capital, Port Harcourt, but there was no obvious link to the election.
The government has labelled critics of the poll coup-plotters and linked them to a failed attempt to blow up the electoral commission headquarters on Saturday with a fuel tanker.
- REUTERS
