Army spokesman Azem Bermendao Agouna said Deby — a longtime Western ally — had died “as a result of his injuries on the front line.”
Rebels, who have been seeking to oust Deby since 2016, had claimed a number of victories in the past week and clashes were reported in the north of the country at the weekend.
Rebels of the Front for Change and Concord in Chad — known in French as Front Pour l’Alternance et La Concorde au Tchad (FACT) — said Friday it had overrun a military garrison in Gouri. The claim was denied by the government, which instead said the rebels had been defeated.
On Monday FACT said that Deby was injured and on the run.
“Faithful to the oath made to the nation and the Chadian people, the Marshal of Chad, President of the Republic, Head of State, Supreme Commander of the Armed Forces, Idriss Déby Itno, has just breathed his last defending the sovereign nation on the battlefield,” Agouna said in his statement. “It is with deep bitterness that we announce to the Chadian people the death this Tuesday, April 20, 2021, of Chadian Marshal Idriss Déby Itno as a result of his injuries on the frontline,” he said.
Agouna said a transitional military council would take charge of the country for 18 months “to assure the defense of our dear country facing this war against terrorism and evil forces”.
Deby’s son, General Mahamat Kaka, will serve as president of the transitional council, according to Agouna.
He promised there would be “free, democratic and transparent elections following the spirit of sacrifice for which the marshal fought during his life.”
The army declared a 14-day period of national mourning and imposed an overnight curfew. Air borders would close until further notice.
The announcement came a day after provisional results suggested Deby, who has been in power for 30 years, had won a sixth consecutive term.
Chad worked closely with Nigeria and Cameroon in the fight against militant group Boko Haram and formed part of a joint taskforce fighting insurgency in the region.
Chad borders Libya, Darfur region of Sudan, Niger, Nigeria, Cameroon and the Central African Republic and there are fears Deby’s death threatens the stability of the region.
FACT claims it is in control of the Tibesti region of Chad, which adjoins Libya.
Mohammed Yahaya, the United Nations Development Programme (UNDP) Resident Representative in Nigeria told CNN: “The worst-case scenario is a Libya type of disintegration in what is a very insecure and conflict affected region. Chad under President Deby’s leadership put a lot of pressure on Boko Haram in the region. If there’s a disintegration would see an increased arms flow and an emboldened Boko Haram, that should concern any policymaker and security actors in Nigeria.”
Yahaya said President Deby played a significant role for the international community as a “security anchor” in the region and their first thoughts would be how to secure an “orderly transition” in the country to avoid further instability.
“Deby was someone the international community relied on to bring security. He also contributed troops to Mali during the insurgency there, so my concern since I heard the news is ‘what’s next?’ and how can the international community ensure and support the country through this difficult transition,” he said.