Zambia's incumbent Edgar Lungu took an early lead following last week's presidential elections, according to the country's Electoral Commission on Saturday.
After counting votes from 22 of the 156 constituencies, President Lungu of the Patriotic Front party (PF) led with nearly 208,000 votes. Opposition leader Hakainde Hichilema of the United Party for National Development (UPND) had approximately 154,000 votes.
Around 6.7 million people were registered to vote in the southern African country on Thursday.
Despite featuring a total of nine presidential candidates, the elections were seen as a two-horse race between Lungu and Hichilema.
Hichilema's party has demanded the immediate release of results and alleged that the ruling party and Zambia's Electoral Commission are attempting to manipulate the vote in favour of Lungu.
Lungu became president after narrowly winning a January 2015 by-election caused by the death of his predecessor, Michael Sata.
Zambia is regarded as one of Africa's most successful democracies, with many peaceful changes of power having taken place since multi-party democracy was introduced in 1990.
But Thursday's elections were preceded by a wave of violence, with clashes erupting between opposition and government supporters and the country's largest independent newspaper, The Post, was meanwhile closed down in what the authorities said was a tax dispute.
Lungu had earlier threatened to mobilize the army if the opposition rejected the results.