Lagos, Nigeria (CNN) It had been a long election campaign, fiercely contested and marked by flashes of violence, but Nigerians were finally looking forward to casting their votes in what is the largest democratic exercise in Africa.

But as they slept, the country's presidential and parliamentary elections were abruptly postponed early Saturday, hours before the polls were due to open.

Polls were set to open at 8 a.m. local time (2 a.m. ET) Saturday. Instead, the vote will take place in another week, on February 23, authorities said, citing logistical issues.

The delay came as a surprise, especially since the chairman of Nigeria's Independent National Electoral Commission had said in an interview earlier this month he could not "foresee any possibility postponement."

"We started this a long time ago and have gone ahead with our preparations. INEC is not even contemplating the postponement of the election," Mahmood Yakubu said, using the acronym for the commission.

Staff of the Independent National Electoral Commission sleep on the ground Saturday in Port Harcourt.

Nigerian President Muhammadu Buhari said in a statement from his hometown of Daura, where he had traveled to vote, that he was "deeply disappointed."

"INEC themselves have given assurances, day after day and almost hour after hour that they are in complete readiness for the elections," Buhari said. "We and all our citizens believed them."

The fallout to the election delay has been swift, with angry Nigerians taking to social media.

"Do they take us as jokes, some people canceled their weddings, parties, some even flew in just for election, goodness gracious, who did we offend in this country?" one Nigerian tweeted as he aired his frustrations over the postponement.

People travelled back to Nigeria from UK, US, Australia etc to vote with return tickets in few days, wedding halls/vendors have been paid for 23rd February & no refunds. Businesses lost money today.



Who's going to bear the cost? INEC or patriotic Nigerians?#ThisIsNigeria — Young Gatsby: Six (@SamuelOtigba) February 16, 2019

A number of registered voters had set out on foot to polling stations Saturday morning as news of the election's postponement slowly trickled out. Some had also slept at polling booths to beat the crowd.

Some schools were closed for a week for security reasons ahead of the elections, while small businesses were shut down after a 6 a.m.-to-6 p.m. curfew was imposed to restrict movement on Election Day.

There was heavy traffic in Lagos, the country's economic capital, on Friday evening as many Nigerians stocked up on food items before the curfew on vehicle movements went into effect. Most of the food and other essential supplies had run out at a popular supermarket that CNN staff visited Friday.

Many business owners lamented they would be forced to close again on February 23, losing crucial revenue three Saturdays in a row, as gubernatorial elections are also scheduled after the presidential elections.

ranked by the With high levels of unemployment and poverty, Nigeria has beenranked by the World Poverty Clock as the country with the largest number of people living in extreme poverty, an estimated 91 million.

Thousands of young Nigerians working as temporary staff for the electoral commission appear to have borne the brunt of Saturday's postponement.

They are members of the National Youth Service Corps, a one-year mandatory program for university graduates in Nigeria.

The corpers, as they are known, provide essential services at polling units during Nigeria's elections, where 84 million people are registered to vote, although turnout is usually much lower.

Many of the youths said they slept in open fields with no security or blankets in unsafe and mosquito-infested areas.

"We slept in open field of primary schools with no security or anything close to a decent shelter. Yet, No apologies," Opeyemi Adeleke, a corps member in Lagos, wrote on Twitter

@atiku @OfficialPDPNig @inecnigeria I am sadden that in Nigeria, some institutions don't value the welfare of their recruits. Year in year out, we either repeat history or get worse. I was a corper PO in 2015 elections and the picture below was my exact condition. We slept in... pic.twitter.com/G0IKVjg033 — Kelvin Newman Ijeomah (@cardinalroyale) February 16, 2019

Femi Akinbiyi, a spokesman for the electoral commission, told CNN that plans had been made for accommodations and food for its temporary staff, but he couldn't confirm if these had been implemented.

"If it is true, we would work on it to make it better before the next election," Akinbiyi said after reports of staffers sleeping in open fields without food.

CNN was not immediately able to reach a National Youth Service Corps representative for comment.