The tightest presidential vote count in Nigeria since the end of military rule in 1999 is currently underway.
Long wait times resulted from polls not opening on time in some areas due to logistical issues and security incidents, which negatively impacted the voting process.
A large number of young, first-time voters showed up early to vote, indicating that turnout was high.
87 million people are eligible to vote, making the elections the largest democratic event in Africa.
Since the return of multi-party democracy 24 years ago, the APC, which is currently in power, and the PDP, have controlled politics.
Peter Obi of the Labour Party, who has the support of many young people, is a strong challenger this time in the race to succeed President Muhammadu Buhari.
Thousands of polling places are currently counting the results, which will then be compiled and sent to the electoral headquarters in Abuja, the nation's capital, for tabulation.
The ultimate outcome is not anticipated until at least Tuesday.
Despite the fact that polling places were supposed to close at 13:30 GMT (14:30 local time), the electoral chief, Mahmood Yakubu, apologized for the delays in voting and said that anyone in line by that time would be allowed to cast their ballots.
While some voters were frustrated with the delays, others patiently waited their turn.
"As a Nigerian, you always prepare for the worst, so I went outside with my power bank and a bottle of water. First-time voter Edith in Lagos told the BBC that she would wait until they arrived before casting her ballot.
In the southern state of Delta and the northern state of Katsina, armed men allegedly attacked some polling places, stealing voter card verification machines in the process.
In order to allow voting to take place, he said, they were subsequently replaced and security was increased.
In Lagos, Nigeria's largest city, there have also reportedly been acts of violence and ballot boxes stolen.
Mr. Yakubu reported that in the Borno state in the northeast, militant Islamists opened fire on election officials from a mountaintop in the Gwoza area, injuring a number of officials.
The run-up to the election was overshadowed by a cash crunch brought on by a botched currency redesign, which resulted in widespread chaos at banks and ATMs as desperate people sought access to their money.
The introduction of the new notes was made in an effort to combat vote-buying and inflation. A House of Representatives member was detained on the night before the election with nearly $500,000 (£419,000) in cash and a list of recipients, according to the police.
Regardless of who wins, they will have to deal with the new currency, a failing economy, high youth unemployment, and pervasive insecurity that resulted in 10,000 fatalities last year.
Additionally, 109 federal senators and 360 members of the house of representatives were up for election, and state governors were also up for election in March.
A third of eligible voters are under 35, which indicates that young people are very interested in this election.
Following his May 2018 joining of the Labour Party, Mr. Obi, 61, hopes to end Nigeria's two-party system.
Although he had previously been a member of the PDP, some young people in Nigeria, particularly those in the south, view him as a relatively new face and give him ardent support.
From 2006 to 2014, the successful businessman presided over the state of Anambra in the southeast. His supporters, known as the "OBIdients," claim he is the only candidate who is honest, but his detractors contend that casting a vote for him is pointless because he is not likely to win.
Instead, the PDP, which ruled until 2015, is urging Nigerians to support Mr. Abubakar, 76, the only significant contender from the region's predominantly Muslim north.
He has previously made five unsuccessful runs for the presidency. Despite his denials, he has been the target of persistent allegations of cronyism and corruption.
Having served as a top official, vice president, and well-known businessman, he has spent the majority of his career in positions of authority.
The person Atiku Abubakar is.
Since the APC has presided over a period of economic hardship and escalating insecurity, the majority of people view the election as a referendum on its leadership.
Its candidate, Mr. Tinubu, 70, is credited with developing Lagos, Nigeria's commercial center, during his two terms as governor from 1997 to 2007.
In the south-west region, where he has significant influence, he is regarded as a political godfather. However, like Mr. Abubakar, he has long been the target of allegations of corruption and poor health, both of which he vigorously denies.
Just who is Bola Tinubu?
For a candidate to be declared the winner, they must receive the most votes and 25% of the total ballots cast in at least two-thirds of the country's 36 states.
If not, a run-off will be held in 21 days, which will be a first in Nigerian history.
* Additional coverage by BBC teams across the nation.
The election commission has posted the results online here:.
