Congo Republic President Denis Sassou Nguesso has been re-elected with 94.82 per cent of the vote, extending his nearly 42 years leading the Central African oil producer.
Diplomats and political analysts had expected an easy victory for Sassou, 82, who was running against six little-known challengers, in an election whose run-up was tightly controlled by the ruling Congolese Labour Party.
The main opposition parties opted not to field candidates, citing a lack of transparency, and two of the best-known opposition figures, General Jean-Marie Michel Mokoko and Andre Okombi Salissa, have been in jail for nearly a decade.
Human rights activists were arrested, several opposition parties were suspended and public gatherings were closely monitored in the run-up to the election, said Joe Washington Ebina, a Congolese human rights activist.
Voting on Sunday was marred by late openings at some polling stations and a nationwide internet blackout.
State television on Tuesday reported turnout of 84.65 per cent, though many polling stations in Brazzaville on Sunday had short lines or no lines at all.
Defeated candidates have five days to file a challenge, and the Constitutional Court has 15 days to examine any challenges before publishing final results.