The tightest election in Nigeria since the end of military rule in 1999 is expected to produce more results soon.
There is growing frustration because only one of the 36 state results has been formally announced thus far.
The electoral commission expressed regret for the results viewing page's inactivity and blamed technical difficulties on an increase in website traffic.
In some areas of the country, the election was held for a second day, which contributed to the delays.
In addition to attacks on some polling places, the election on Saturday saw voting begin several hours later than scheduled in many places.
The largest democratic exercise in Africa, with a participation eligibility of over 87 million, took place.
An unprecedented challenge to the two-party system that has ruled Nigeria for 24 years was made during the election.
Atiku Abubakar of the main opposition Peoples Democratic Party (PDP), Bola Tinubu of the ruling All Progressives Congress (APC), and Peter Obi of the previously unknown Labour Party are all viewed as potential winners. There are 15 additional presidential contenders.
Only one result has been made public thus far, and it came from the southwest Nigerian state of Ekiti, where Mr. Tinubu easily won in one of his strongholds.
In the last two elections, a winner has only been declared on the third day after voting; however, many had anticipated a quicker conclusion this time around due to the implementation of an electronic result transmission system.
This was done in an effort to increase transparency and ensure that the results could not be tampered with by posting a digital copy on the website of the electoral commission, Inec.
However, many voters have accused election officials of failing to upload the results as they are required to do at the polling places.
Voters have shared videos and images in places where Inec officials refused to upload the results, despite complaints from officials about some locations' lack of internet access.
Additionally, there have been reports of unrest at Inec collation centers in some states, and some political parties on Sunday urged their supporters to go there to safeguard their votes.
