Dozens of people traversing the Sahara desert on their way to Europe are feared to have died of thirst in Niger, officials say.
Five bodies have been found, while a further 35 are missing after their vehicle broke down and they set off to seek help, said the Agadez governor.
Agadez lies on one of the main migrant routes from West Africa to Europe.
Hundreds of migrants have died this month when their boats sank as they tried to cross the Mediterranean Sea.
Agadez mayor Rhissa Feltou said two vehicles had left the town of Arlit, north of Agadez, earlier this month, carrying "at least" 60 migrants.
The convoy was heading for Tamanrassett, an Algerian town in the heart of the Sahara, he said.
The mayor of Agadez said that after one vehicle broke down, passengers went to look for spare parts and bring them back for repairs.
He said the migrants broke up into small groups and started walking.
Days later, the survivors who reached Arlit, a centre for uranium mining, alerted the army, but troops arrived too late at the scene, he added.
The authorities have called off the search for the missing.
They consisted of "entire families, including very many children and women," Azaoua Mamane, who works for the non-governmental organisation Synergie in Arlit, told the AFP news agency.
The bodies found are of two women and three girls aged 9-11.