A number of people have been killed and wounded in a fire that erupted at a huge military ammunition depot in Chad's capital N'Djamena, President Mahamat Idriss Deby Itno said on Wednesday.

The blaze "caused human and material damage," Deby wrote on Facebook.

"Peace to the souls of the victims, sincere condolences to the grieving families and a speedy recovery to the wounded," Deby wrote, promising to open an investigation into the fire.