Around 10 migrants from Niger have died of thirst and 50 are missing after one of the vehicles that they were travelling in broke down in the Sahara.
Although the number of West Africans seeking to reach Europe has dropped in recent years, the route across the Sahara is still used by some migrants from the region and those from farther afield.
Hundreds of those who make it to the Mediterranean have drowned trying to cross in recent months.
The governor of the desert region of Agadez Garba Maikido said that: "Two vehicles left for a neighbouring country and when one of them broke down, ten people sadly died,"
He said: "About 50 people are still missing and only about 15 were saved."
Earlier in the day, the mayor of the town of Arlit, Maouli Abdouramane, north of the capital of Agadez, said survivors who had managed to return to Arlit had alerted the authorities.
The migrants had set off across the Sahara towards Algeria in mid-October, but scattered to find water after their vehicle broke down.
More than 32,000 migrants have arrived in southern Europe from Africa so far this year.
Refugees from the civil war in Syria have added to the flow of migrants looking for a better life in Europe.
Two separate incidents in southern Italy earlier this month underscored the dangers involved when 366 Eritrean migrants drowned in one disaster.
Around 200 were missing after another boat sank just over a week later.