Lagos, Nigeria (CNN) Nigerians are expected to cast their ballots on Saturday, seven days after the country's presidential and parliamentary elections were abruptly postponed just hours before polling stations opened.

It marked the third time in row that a vote has been delayed in Nigeria.

Why was this vote postponed?

With 84 million people registered to vote in the country, its Independent National Electoral Commission (INEC) has the mammoth task of overseeing the voting process in Africa's largest democracy.

Early on February 16, INEC's chairman said that after a review of the "logistics and operational plan," proceeding with the vote that day was not feasible.

The fallout was swift, with the two main political parties blaming one another. Nigeria is also counting the economic cost of delaying the elections, which has been put at more than $2 billion , according to analysis firm SBM Intelligence , which estimates that Nigeria lost 0.531% of its $420 billion gross domestic product.

Will the elections really go ahead on Saturday?

Many figures, such as Bayelsa State Governor Seriake Dickson , expressed concern that one week isn't enough time for the INEC to deal with the concerns they expressed previously.

The delay also comes with a new set of logistical challenges. For example, the dates on thousands of electronic card readers for biometric voting were all required to be changed to the new election date. INEC says that it has now reconfigured 100% of these readers and is on track to deliver voting materials to states that didn't originally have them.

While voting looks likely to go ahead, there are fears of low voter participation on Saturday, including those expressed by INEC itself. Spokesman Festus Okoye told local media on Monday, "We are worried about voter turnout."

Many Nigerians travel from major cities such as Lagos and Kano to their home towns or villages to vote where they are registered. Some are unlikely to make another trip after last week's wasted journey or will be unwilling to pay to travel again.

In an effort to get out the vote, the government has declared the eve of the elections a public holiday and airlines are offering discounts. Groups are also organizing free "buses for democracy," to help combat voter apathy.

What about the threats of violence?

The delay has increased tensions in this crucial vote and there has been some violence in the lead-up, prompting warnings from the British and US governments that they would deny visas to, and could prosecute, anyone found inciting violence during the election.

A terror group with links to ISIS claimed responsibility for a deadly February 12 attack on a motorcade carrying the governor of Nigeria's northeastern Borno state. Governor Kashim Shettima escaped unscathed and Isa Gusau, his media aide, told CNN on Thursday that the ambush killed three people, although locals put the figures much higher.

The Islamic State's West Africa Province terror group, a breakaway faction of Boko Haram, has staged a number of high-profile attacks in recent months.

Normal life has been put on hold nationwide for the elections, with borders closed and drivers urged not to take their cars on the roads.

Curfews will also be in place across Nigeria ahead of Saturday's elections.

President Muhammadu Buhari this week ordered the military to be ruthless with anyone attempting to rig or snatch ballot boxes, as can sometimes happen in Nigeria. He also said anyone attempting voter fraud is doing so "at the expense of their lives."

One of the president's key allies, Nasir El-Rufai, was widely condemned after he said foreign observers who interfered in the country's elections would "go back in body bags."

What is at stake?

Buhari, 76, is running against 71 other presidential candidates but his main challenger is Atiku Abubakar, a 72-year-old business tycoon and former vice president. They are both Muslim candidates from the north of the country.

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When Buhari, a former military ruler, was elected in 2015 it was the first peaceful transition of power in the country. He promised to be a new broom, offering a clean sweep of the old routine but many have been left disillusioned and angry at the rising levels of inequality and extreme poverty.

An estimated 91 million Nigerians are now impoverished, the highest number in any country in the world, according to The Brookings Institution.

The latest vote comes at a critical time for the country's economy. The recent oil price crash sent Nigeria's economy into turmoil when the price of a barrel plunged to $40 at its lowest from a high of $100, leaving the country's major revenue source depleted.

To be elected, either Buhari or Abubakar (or another very unlikely candidate) must receive the majority and more than 25% of the vote in at least 24 of the country's 36 states. It will go to a second round if no one receives this required number.

Political strategist George Ajjan said having two northern Muslim candidates is good for Nigeria's democracy as it "removes religion and region from the sentiments of voters."

"Now, voters can consider which party's platform has more to offer, rather than 'I'm voting for the guy who talks or prays like me,'" said Ajjan.