President Idriss Deby of Chad is dead.

Deby was aged 68. He died while “defending the sovereign nation on the battlefield,” over the weekend, according to army spokesman General Azem Bermandoa Agouna in a statement on state television.

The Chadian army has been battling rebel forces, which launched an assault on the capital, N’Djamena.

Deby, who ruled Chad since 1990, died of wounds suffered on the frontline during a battle against rebels in the country’s north who were advancing on the country’s capital, Ndjamena, Agouna said.

Deby was killed a day after he was declared winner of a presidential election that would have given him a sixth term in office.

The exact circumstances of Deby’s death were not immediately clear.

The deceased president had been commanding his army at the weekend as it battled rebels who had launched a major incursion into the north of the country on election day on April 11.

Reports say Deby will go down in history as one of Africa’s longest-ruling leaders, surviving numerous coup attempts and rebellions.