Chad’s President Idriss Deby, 68, died while commanding troops on the front line of a fight against northern rebels, an army spokesman said on Tuesday.
The announcement came a day after he was declared the winner of a presidential election for a sixth term.
The military said Deby had been commanding his army at the weekend as it battled against rebels who launched a major incursion into the north of the country on election day.
Deby, who was in power for four decades, “has just breathed his last defending the sovereign nation on the battlefield” at the weekend, army spokesman General Azem Bermendao Agouna said in a statement read out on state television.
The cause of death was not yet clear.
Deby’s son, General Mahamat Kaka, 37, was named the interim head of state and will lead the National Council of Transition, said Gen Agouna.
The military council now headed by Gen Kaka has already met to draw up a transitional charter, Gen Agouna said as he announced a curfew and border closures as well as the dissolution of the civilian government and elected Parliament.