Celebratory gunshots rang out in the capital of the Central African nation of Chad on Thursday night after its military ruler, President Mahamat Idriss Déby, was declared the winner of a highly scripted presidential election on national television.

Two hours before the official broadcast, a “resounding victory” had been claimed by his main challenger, Succès Masra, the opposition leader who has been the country’s prime minister since January, after he returned from exile abroad and made a deal with Mr. Déby.

But the preliminary results announced by Chad’s National Elections Management Agency depicted a resounding victory for the other side. Mr. Déby, it said, won 61 percent of the vote, and Mr. Masra 18.5 percent.

Nine people were killed after the celebratory volleys were fired in Ndjamena, the capital, according to several local media reports, including four children from the same family. This was despite a ban on gunfire and parades, according to an internal message from the army that was circulating in Chad on Thursday.

Many analysts saw the result of Chad’s election as a foregone conclusion, and one that had been masterminded by a supposedly transitional government that never had any intention of relinquishing power.

Mr. Déby — who took power after his father and predecessor, Idriss Déby Itno, died on the battlefield in 2021 — had promised not to run for election. But he did, and against a field that was reduced in number by the disqualification of several prominent candidates and the shooting death of another two months before the vote.

One of a strip of countries in Africa’s arid Sahel region ruled by a military junta after a coup, the landlocked nation of roughly 18 million people has never had a free and fair election. Civil society groups, opposition members and some election observers condemned violence and fraud in Monday’s election, and there were allegations of ballot-box stuffing.

In a live broadcast on his Facebook page, Mr. Masra called upon his supporters to “mobilize peacefully.”

“You already know the results of this election, because they’re your results,” he said, reading from a tablet, a Chadian flag behind him. “You have voted for change.”

But anyone venturing into the streets of Ndjamena on Thursday night was met with a military presence that was heavily armed, unusually so even for Chad. Eighteen months ago, dozens of protesters were killed as they demanded change during demonstrations set off by the junta’s decision to extend its stay in power.

Mahamat Adamou contributed reporting from Ndjamena, Chad.