Central African Republic President Faustin-Archange Touadera has won re-election after the first round of voting, the electoral commission announced on Monday.

The 63-year-old incumbent won "an absolute majority" of the December 27 vote with 53.9 percent and is "declared elected", National Elections Authority (ANE) chief Mathias Morouba told reporters.

In a field of 15 contenders, the runner-up was former prime minister Anicet Georges Dologuele, who scored 21.01 percent, Morouba said.

The constitutional court will validate the result after any disputes are resolved. Last Wednesday, the opposition called for the vote to be annulled, calling it badly flawed.

Dologuele immediately cried foul, telling AFP: "It’s a farce. There were many irregularities and instances of fraud."

The presidential election, which coincided with legislative polls, took place against the backdrop of a new offensive by a coalition of armed rebel groups, with thousands of voters unable to cast their ballots.

According to official figures, voting did not take place at all in 29 of the country’s 71 sub-prefectures and was curtailed in six others.

However, the ANE reported on Monday that turnout had reached 76.31 percent.

Touadera’s government controls only about one-third of the former French colony, with militia groups that emerged from a conflict in 2013 controlling the remainder.

Earlier on Monday, CAR prosecutors said an investigation had been launched into former president Francois Bozize, accused by the government of plotting a coup with the help of armed groups ahead of the elections.

President Touadera has won elections: Photo Reuters