Partial results in Bangui from Wednesday’s election showed Touadera, a former prime minister under ousted ex-president Francois Bozize, leading with 30 999 votes.
Anicet Georges Dologuele, another former prime minister who had been seen as one of the favourites to lead the country, was on 28 162 votes while Desire Kolingbala, son of former military dictator Andre Kolingba, had 25 057.
The results were based on nearly 130 000 votes, representing 64% of votes cast in Bangui, Julius Ngouade Baba of the National Elections Authority (ANE) told reporters.
Voters had flocked to the polls to elect a president and parliament, three years after the ousting of Bozize, a Christian, by a rebel alliance dominated by minority Muslims.
Despite security concerns after a deadly attack on a Muslim district in Bangui during a mid-December constitutional referendum the election went off without major incident after initial delays caused by logistical glitches.
Nearly two million people in the country of around five million were eligible to choose between around 30 presidential hopefuls and over 1 800 people running for a place in the 105-seat National Assembly.
The head of the UN’s Minusca peacekeeping mission in CAR, Parfait Onanga-Anyanga, hailed the election as a success.
The presidential election is expected to go to a run-off on January 31.
One of the poorest countries in the world, with a history of coups and rebellions, CAR was plunged into a bout of fierce intercommunal violence in 2013 after Bozize was ousted by the Seleka rebel alliance.
Thousands of people were killed and around one in ten fled their homes in attacks by rogue rebels on remote villages and the fierce reprisals by Christian militia against Muslim communities.
UN and French peacekeepers helped restore a degree of calm in January 2014, when a transitional government took over, but large parts of the country which was visited by Pope Francis by November remain lawless.
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