Nigerians awoke on Saturday to find that the country’s presidential election had been delayed until February 23 because of what the electoral commission called unspecified “challenges”.

The top candidates condemned the decision and blamed each other but appealed to Africa’s largest democracy for calm, while they rushed back to the capital, Abuja, to learn more about what went wrong.

Nigeria Election
A man reads a newspaper which managed to print the news of the postponement in time (Ben Curtis/AP)

The postponement was announced a mere five hours before the polls were to open. The decision is a costly one, and authorities now must decide what to do with already delivered voting materials in a tense atmosphere where some electoral facilities in recent days have been torched.

Some bitter voters in the capital and elsewhere, who had travelled home to cast their ballots, said they could not afford to wait another seven days. They warned that election apathy could follow.

Nigeria Election
A police officer keeps guard over electoral materials still stacked in boxes at the offices of the Independent National Electoral Commission in Kano (Ben Curtis/AP)

The party backing top opposition challenger Atiku Abubakar accused President Muhammadu Buhari’s administration of “instigating this postponement” with the aim of ensuring a low turnout at the polls.

“Their plan is to provoke the public, hoping for a negative reaction, and then use that as an excuse for further anti-democratic acts,” the party said in a statement. It urged Nigerians to remain calm and turn out in greater numbers a week from now.

Nigeria Election
Nigerian presidential candidate Atiku Abubakar, of the People’s Democratic Party, speaks to journalists after the election was delayed by the Independent National Electoral Commission (Sunday Alamba/AP)

A calm-looking Mr Abubakar, speaking to reporters outside his home in northern Adamawa state, said his party would decide on the way forward after an electoral commission briefing on Saturday afternoon. A party spokesman in Delta state in the volatile south said the commission “has destroyed the soul of Nigeria with this act”.

Mr Buhari said he was “deeply disappointed” after the electoral commission had “given assurances, day after day and almost hour after hour that they are in complete readiness for the elections. We and all our citizens believed them.”

Nigeria Election
Nigerians discuss the overnight developments (Ben Curtis/AP)

His statement appealed to Nigerians for calm during the “trying moment in our democratic journey” and stressed that his administration does not interfere in the commission’s work.

One ruling party campaign director in Delta state, Goodnews Agbi, told The Associated Press it was better to give the commission time to conduct a credible vote instead of rushing into a sham vote “that the whole world will criticise later.”

Nigeria Election
Mahmood Yakubu, chairman of the Independent National Electoral Commission, announces the delay to the presidential election (AP)

Commission chairman Mahmood Yakubu said in the early-morning announcement: “This was a difficult decision to take but necessary for successful delivery of the elections and the consolidation of our democracy.”

Frustrated voters gathered in the capital.

“I came all the way from my home to cast my vote this morning … and then I got informed that the election has been cancelled, so that is the reason why I am not happy, and I’m very, very angry,” voter Yusuf Ibrahim said.

Nigeria Election
Nigerian police officers guard the Independent National Electoral Commission office in Kaduna (Jerome Delay/AP)

Elsewhere, some Nigerians turned to playing football instead, or anguishing over rescheduling weddings, exams and other milestones because of the voting delay.

A civic group monitoring the election, the Situation Room, said the delay “has created needless tension and confusion” and called on political parties to avoid incitement and misinformation.

Nigeria Election
Nigerians check voters’ lists at a polling station in Kaduna (Jerome Delay/AP)

Nigeria postponed the previous presidential election in 2015 because of deadly insecurity in the north-east, which remains under threat from Islamic extremists.

More than 84 million voters in the country with a population of some 190 million had been expected to head to the polls in what is seen as a close and heated race between Mr Buhari and Mr Abubakar, a billionaire former vice president.

Nigeria Election
President Muhammadu Buhari (left), pictured with party official Mustapha Dankadai, faces a challenge from opposition candidate Atiku Abubakar (Ben Curtis/AP)

Both have pledged to work for a peaceful election even as their supporters, including high-level officials, have caused alarm with vivid warnings against foreign interference and allegations of rigging.

When Mr Buhari came to power in 2015 he made history with the first defeat of an incumbent president in an election hailed as one of the most transparent and untroubled ever in Nigeria, which has seen deadly post-vote violence in the past.

Nigeria Election
Youth supporters of President Muhammadu Buhari cheer as they return from a rally (Ben Curtis/AP)

Now he could become the second incumbent to be unseated. This election is a referendum on his record on insecurity, the economy and corruption, all of which he has been criticised by some Nigerians for doing too little too slowly.