Chad's military ruler Mahamat Déby has been declared the official winner of the presidential elections, legitimising his grip on power.

Gen Déby won 61.3% of the vote, according to the state's election body, citing provisional results, while his closest rival, Prime Minister Succes Masra, won 18.53%.

Mr Masra had earlier declared that he had won a "resounding victory" in the first round of voting, and that victory had been stolen "from the people".

Gen Déby, 40, was installed as Chad's leader by the military after his father, Idriss Déby Itno, was killed during a battle with rebel forces in April 2021.

His victory means that the Déby family's 34-year-rule will continue.

The results of Monday's election were announced two weeks earlier than expected.

They are due to be confirmed by the constitutional council.

Just before the election results were announced, Prime Minister Masra claimed victory in a live broadcast on Facebook, and called on his supporters and security forces to oppose what he said was an attempt by Gen Déby to "steal the victory from the people".

"A small number of individuals believe they can make people believe that the election was won by the same system that has been ruling Chad for decades," he said.

"To all Chadians who voted for change, who voted for me, I say: mobilise. Do it calmly, with a spirit of peace," he added.

Chad becomes the first of the countries where the military seized power in West and Central Africa in recent years to hold elections and restore civilian rule.

But critics say with the election of Gen Déby, little has changed.

Monday's voting was mostly peaceful but at least one voter was killed, according to local media.

There had also been some opposition reports of irregularities on polling day.

Ten politicians who had been hoping to run were excluded by the constitutional council because of “irregularities”, which some say was politically motivated.

Another potential opponent, and a cousin of Gen Déby, Yaya Dillo, was killed by security forces in February while allegedly leading an attack on the National Security Agency in the capital, N’Djamena.

Activists had called for a boycott of the election.

Many are still in exile following a deadly crackdown on opponents following protests in October 2022.

The oil-exporting country of nearly 18 million people has not had a free-and-fair transfer of power since independence from France in 1960.

Idriss Déby overthrew Hissène Habré in 1990 and remained in charge for the following three decades until his battlefield death in April 2021 at the age of 68.

Gen Déby initially pledged to stay as interim leader for just 18 months, a period that was later extended. He also said that he would not run for president.