Nigerians discuss the postponement of the national voting day around a daily newspapers vendor on February 16, 2016 in Lagos. Picture :AFP/STEFAN HEUNIS
Nigerians discuss the postponement of the national voting day around a daily newspapers vendor on February 16, 2016 in Lagos. Picture :AFP/STEFAN HEUNIS

Daura/Yola — Nigeria's president and the leading opposition candidate urged people to remain calm after a national election scheduled for Saturday was postponed by a week just five hours before polls were due to open.

However, the opposition candidate, former vice president Atiku Abubakar, later accused President Muhammadu Buhari of instigating the delay in order to "disenfranchise" the electorate.

Early on Saturday morning, just as Nigerians began heading out to polling stations, the chairman of the electoral commission said it was no longer feasible to hold free and fair elections on Saturday due to logistical problems.

The vote will now be held on February 23, the chairman said.

But the delay still threw the country into renewed political uncertainty.

Electoral commission officials and Western diplomats said the problems concerned the inability to transport ballot papers and results sheets to some parts of the country, where 84-million voters have registered to vote.

Buhari, in power since 2015, faces a tight election contest against the People's Democratic Party's Atiku.

At stake is control of Africa's top crude oil-producing nation and largest economy.

Past elections in Nigeria have been marred by violence, intimidation and ballot-rigging, and the postponement raised the possibility of unrest.PDP chairman Uche Secondus said the move was "dangerous to our democracy".

He called it part of an attempt by Buhari to "cling on to power even when it's obvious to him that Nigerians want him out".Atiku and Buhari both sought to avert any violent protests or confrontation.

The president, who was Nigeria's military ruler in the early 1980s, said in a statement he was "deeply disappointed" and urged Nigerians to "refrain from all civil disorder and remain peaceful, patriotic and united".

Atiku told reporters at his residence in the northeastern city of Yola that he was shocked by the electoral commission's decision. He urged voters to be patient and wait until next Saturday to cast their ballots.

But he later said that Buhari's administration was behind the delayed elections, without offering any evidence."

By instigating this postponement, the Buhari administration hopes to disenfranchise the Nigerian electorate in order to ensure that turn out is low on the rescheduled date," he said on Twitter.

Buhari's spokesman Garba Shehu declined to comment.

Presidential elections in 2011 and 2015 were also delayed over logistics and security issues.

Bismarck Rewane, economist and CEO of Lagos-based consultancy Finance Derivatives, said: "No matter who wins, it is now far more likely that the loser will contest the result and argue that the election has been compromised because sensitive materials are out there."

Situation Room, an organisation of more than 70 civil society groups, said the postponement "had cast a cloud of doubt on (the commission's) credibility and competence in conducting the election" and "created needless tension and confusion in the country".

Six dead in Maiduguri

Voters across Nigeria also said they were unhappy. In the northeastern city of Maiduguri, people gathered for morning prayers after which they had planned to vote.

"We are disappointed and deeply pained by the postponement of the election. We spent our all night without sleeping hoping to vote today and just hearing the news that the election was been postponed," said one worshipper, Auwolu Usman.

Kabiru Sale, 27, who sells oil in the northern city of Kano, said the move took him by surprise.

"I am not happy with the suspension. I had already gone out to cast my vote only to be told on the way about the suspension. I do not really understand why they suspended the election," he said.

Six people were killed in a bomb blast in Maiduguri by suspected Islamist militants on Saturday morning, according to the State Emergency Management Agency, even though authorities had bolstered security in much of the country.

Maiduguri is the capital of Borno, the state worst hit by the Boko Haram militant group and its offshoot, Islamic State in West Africa Province.