That's it for our live coverage of this historic vote. Counting has started in places, but in some areas voting will continue on Sunday because of technical problems. The BBC's Focus on Africa will have a round-up of the day at 19:00 GMT on the World Service and you can find the latest news on BBCAfrica.com.

Image source, AP

Here's a photo from the BBC team in Abuja of election officials counting votes by torchlight on a street in the capital city.

Andrew Harding
Africa correspondent

We've seen the impressive patience, discipline - and in the troubled north-east, pure courage - shown by most voters in most areas.

Image source, AFP

A picture of counting at a polling station in the northern city of Kano after dark, taken by BBC Hausa service's Yusuf Yakasai.

Nkem Ifejika
BBC World Service, Abuja

tweets, external: "Darkness has fallen. #NigeriaDecides #shineyaeye

Stephanie Hegarty
BBC World Service, Abuja

tweets, external: "Reports of ballot boxes being stolen.. And Inec observers kidnapped.. Not too widespread though, overall so far so good #NigeriaDecides"

Nigeria's ruling PDP party says it is concerned by reports of under-aged persons being accredited to vote in some northern states, seen as opposition strongholds.

In a statement, it also denounced as a "huge national embarrassment" the failure of card readers to verify President Jonathan and other politicians as voters and said it will demand a "thorough explanation" from the electoral commission.

Here's a video of the two main presidential candidates talking to the BBC after casting their votes.

Will Ross
BBC Nigeria correspondent

tweets, external: "Does any country in the world go into the lockdown mode for elections like Nigeria? No-one allowed to drive on roads."

Kelvin Brown
BBC News, Daura

tweets, external: "Still loads of people waiting to vote in the neighbourhood where #Buhari grew up. #NigeriaDecides"

There are reports of electoral materials being snatched in an area of south-eastern Ebonyi state.

"The hoodlums, wielding AK-47 riffles, emerged from the bush and shot into the air to scare voters and officials away before snatching the materials," Nigeria's Premium Times newspaper reports, external.

Patrolling soldiers are snapped by the BBC's Chris Ewokor in the town of Mararaba in Nasarawa state, near the capital Abuja. Chris will be on the BBC's Focus on Africa at 19:00 GMT talking to voters about their experiences.

Image source, Reuters

An electoral worker eats his lunch next to ballot boxes in a polling station in the northern city of Kano.

Military helicopters hovered above voters queuing at a polling station in Maiduguri, the former headquarters of Boko Haram, Reuters news agency reports.

"I'm not afraid of violence. I don't even expect any problem," 27-year-old student Kaulala Abbas is quoted as saying. "I've decided like most people to effect a change in government and this can only be done through my vote."

Image source, AP

Here's a video round-up of the key points from the day's voting.

BBC cameraman Jack Garland tweets, external, "Women in Lagos stare at an SSS (state security service) agent watching them queue to vote. #bbcnews #NigeriaDecides!

Becky Lipscombe
BBC News, Abuja

"Don't fold your ballot like this," says electoral official Hamza Umar in Abuja, "or the ink might smudge and you'll end up voting for someone else."

After casting his ballot in Daura, Gen Buhari told the BBC's Abduallahi Kaura Abubakar that the voting process was "in order".

He added: "But I have been watching activities in other states which is disappointing, but overall it's on course."

The elections were postponed by six weeks to give regional forces time to recapture territory from Boko Haram. On Friday, Nigeria's military said the group had been driven out from virtually all the towns it controlled in the north-east. Boko Haram denounced the elections as un-Islamic.

News is coming in of 23 people being beheaded in the north-eastern town of Buratai on the eve of the election.

The AFP news agency is quoting the lawmaker who represents the town, Mohammed Adamu, as saying that suspected Boko Haram militants carried out the attack.

Homes were also burnt in Buratai, some 200km (125 miles) from Maiduguri, the capital of Borno state, Mr Adamu told AFP.