Results from the Central African Republic presidential election show former Prime Minister Faustin Touadera has a surprise lead with a quarter of votes counted.
Thirty candidates contested the poll, which is likely to go to a run-off on 31 January.
He was prime minister in the government of ex-President Francois Bozize, ousted in 2013 by mainly Muslim Seleka rebels.
The country has since been wracked by conflict along religious lines.
More than a quarter of the population has been forced from their homes.
Voting took place on 30 December, with UN troops guarding polling stations.
Mr Touadera has more than 23% of votes counted so far with his nearest rival, Anicet Georges Dologuele, another former prime minister, on around 13%, according to electoral officials quoted by the AFP news agency.
Desire Kolingba, son of a former president, is in third place.
But the votes cast outside the capital, Bangui, as well as those of refugees and other CAR citizens abroad still need to be counted.
The candidates are vying to replace interim leader Catherine Samba-Panza.
Mr Touadera, 58, was a university maths lecturer before entering politics. He ran as an independent in the election.
CAR has been torn by sectarian violence since the Seleka rebels seized power in March 2013.
A band of mostly Christian militias, called the anti-Balaka, then took up arms against the Seleka.
The interim government and international donors pushed for the poll, believing that an elected president and parliament would help CAR recover from years of unrest.
CAR is one of the world's poorest countries - yet it is rich in natural resources.
Elections also took place for the 149-seat National Assembly.
After seizing power, the Seleka rebels installed Michel Djotodia as the first Muslim leader of the majority Christian country.
But under pressure from regional leaders and former colonial power France, Mr Djotodia stood down and was succeeded by Ms Samba-Panza.
About 1.8 million people were registered to vote, out of a population of roughly five million.
More than one million people fled their homes during the intercommunal fighting.