The vote was intended to complete Guinea's transition to democracy after decades of dictatorship and strongman rule. It had been delayed by nearly two years because of disputes over how it would be conducted.
Results had been expected within 72 hours of polling closing, but election officials later said that the 72-hour window would not start until they had received all results.
Both sides have accused the other of using the election results delay to tamper with the vote, and have vowed to bring the matter to court. The two political parties draw their support along ethnic lines, and both make up about 35 percent of the population.
Guinea's 2010 presidential election pitted Peul candidate Cellou Dalein Diallo against Malinke politician Alpha Conde, who ultimately won the presidency.
As word spread that Diallo had lost, his supporters began burning tires, throwing rocks at passing cars and setting fire to the homes of Malinke neighbors. Over the next three days, security forces systematically attacked Peul communities, spraying populated areas with bullets.