Former military ruler Muhammadu Buhari has become the first opposition candidate to win presidential elections in Nigeria.
Gen Buhari’s party said his opponent, incumbent Goodluck Jonathan, had admitted defeat and congratulated him.
Jonathan trailed Gen Buhari by about two million votes when he conceded.
Observers have generally praised the election but there have been allegations of fraud, which some fear could lead to protests and violence.
“President Jonathan called General Muhammadu Buhari, the winner of the elections, to congratulate him,” Lai Mohammed, a spokesman for Gen Buhari’s All Progressives Congress (APC), said.
The spokesman praised Jonathan, saying: “He will remain a hero for this move. The tension will go down dramatically.”
“Anyone who tries to foment trouble on the account that they have lost .This is a hugely significant moment in Nigeria’s turbulent history. Never before has a sitting president been defeated in an election.
Since independence from Britain in 1960, there have been numerous coups and most elections have been rigged. Of course in a close election there will be many voters who are not pleased with this outcome but the whole process is a sign that democracy is deepening in Nigeria.
The poll has once again brought to the surface dangerous religious and regional differences and there is still a threat of violence.
The man who has been voted out, Goodluck Jonathan, has played a huge part today in trying to prevent that. He made the phone call when there would no doubt have been some in his camp who would have preferred to dig their heels in.