Chadians are due to go to the polls on Sunday in legislative and local elections which the government of President Mahamat Debby Itno presents as a key step towards a democratic transition.
However, opposition parties have dismissed the planned elections as a sham.
Voting is taking place against a backdrop of recurring attacks by Boko Haram in the Lake Chad region, the ending of a military accord with former colonial ruler, France, and an influx of refugees fleeing the conflict ravaging neighbouring Sudan.
The 40-year-old Mahamat Deby took power in 2021 after the death of his father, Idriss Deby Itno, who had ruled the poor Sahel country with an iron fist for three decades.
Deby junior won a five-year presidential mandate last May in a vote the opposition denounced as fraudulent.