Fifty-two migrants have been found dead in the deserts of central Niger, near Séguédine.
A group of 75 set out in three vehicles but were abandoned by traffickers, who feared the security forces.
A local official told the BBC that dozens of bodies had been buried, and 23 survivors were taken to the town, although one later died.
African migrants travel through the desert aiming to reach Libya and cross the Mediterranean to Europe.
However, the journey is perilous as the migrants are crammed into pick-up trucks and have few supplies.
Two weeks ago Niger troops rescued 92 migrants who were on the brink of death in the Sahara Desert.
The group, which included women and children, was abandoned without water and food.