At least nine people were killed and more than 46 injured in blasts caused by a fire at a military ammunition depot in Chad's capital on Tuesday night, health minister Abdelmadjid Abderahim said.

The death toll could rise as many people suffered serious injuries, Abderahim told reporters on Wednesday.

The explosions lit up the night sky over the military base near the central African nation's main international airport and sent spent shells flying into nearby homes where terrified residents struggled to find cover.

On Wednesday morning President Mahamat Idriss Deby visited the site where wrecked cars and twisted metal littered the ground around a crater.