The military spokesman, Azem Bermandoa Agouna, said on Tuesday that Déby died while protecting the country's territorial integrity, according to AFP, Sputnik reported.
A source familiar with the situation has confirmed to Sputnik that the president of Chad was injured during clashes and died in hospital.
Déby was a commander of an army unit during the hostilities against the rebels in the north of the country.
According to Sky News Twitter, the Chadian military has confirmed the news of the killing of the country's president, and the country's official television has officially announced the news.
The news comes just hours after provisional results of the 11 April elections showed that the 68-year-old political veteran had won 80 percent of the vote and was heading for a sixth term in office.
No further details have been released.