Touadera secured more than 53 per cent of votes in an election marred by violence, according to provisional results announced on Monday.

The electoral commission declared Touadera the winner of the December 27 election, saying he had secured enough votes in the first round to make a second round run-off unnecessary in the gold- and diamond-producing country.

The 63-year-old has struggled to wrest control of vast swathes of the country from armed militias since winning power in 2016, three years after former President Francois Bozize was ousted by another rebellion.

The presidential election went ahead despite an offensive by rebels who tried to disrupt the vote after Bozize's candidacy was rejected by the country's highest court.

"Faustin-Archange Touadera, having received the absolute majority of the vote in the first round with 53.9 per cent, is declared winner," electoral commission's president Mathias Morouba, told media in Bangui.

He said about half the country's electorate had registered to vote and turnout among the registered voters was 76.3 per cent.

Provisional results of a legislative election held the same day will be announced at a later date.

Separately on Monday, prosecutors said an investigation had been launched into Bozize's role in the rebellion intended to disrupt the election.

Bozize and other accomplices were being investigated for crimes including sedition, rebellion, assassination and theft, they said in a statement.

Bozize could not ibe reached for comment.

His party had previously denied the government's accusations the former president was plotting a coup but some in the party have suggested they are working with the rebels.

The vast but sparsely populated country of 4.7 million has struggled to find stability since Bozize was ousted in 2013.

Australian Associated Press